Impact of erector spinae muscle mass and quality on decline in swallowing function during hospitalization in older patients with pneumonia: single-center retrospective observational study in Japan

Impact of erector spinae muscle mass and quality on decline in swallowing function during hospitalization in older patients with pneumonia: single-center retrospective observational study in Japan | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Impact of erector spinae muscle mass and quality on decline in swallowing function during hospitalization in older patients with pneumonia: single-center retrospective observational study in Japan Yuichi Murakawa, Akira Tamaki, Ryota Matsuzawa, Shinjiro Miyazaki, and 5 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9201548/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background: Trunk muscle mass and quality may be related to swallowing function; however, it is unclear whether the same trend is observed in older patients with pneumonia. We aimed to determine the impact of the mass and quality of the erector spinae muscles (ESM), measured by chest computed tomography (CT), on the decline in swallowing function during hospitalization in older patients with pneumonia. Methods: The participants were patients hospitalized at Sanuki Municipal Hospital with a diagnosis of pneumonia who underwent pulmonary rehabilitation. The cross-sectional area of the ESM (ESM CSA /BSA) was measured using chest CT images as an indicator of muscle mass, and the CT value of the ESM (ESM CT ) was measured as an indicator of muscle quality. After calculating the cutoff values of ESM CSA /BSA and ESM CT that predict a score of ≥2 on the Functional Oral Intake Scale (FOIS), we classified the participants (n=452) into four groups: High ESM CSA /BSA・ESM CT , Low ESM CSA /BSA, Low ESM CT , and Low ESM CSA /BSA・ESM CT . Results: Multiple logistic regression analysis, adjusted for confounders, showed that Low ESM CSA /BSA was significantly associated with FOIS change during hospitalization. Conclusions: Our results suggest that muscle mass is strongly associated with a decline in swallowing function during hospitalization in older patients with pneumonia. pneumonia erector spinae muscle muscle mass muscle quality swallowing function Figures Figure 1 Figure 2 Introduction Recently, Japan's population has been aging more rapidly than that of other countries. There is a close relationship between the aging of the population and the incidence of pneumonia [ 1 ]. Many older patients with pneumonia reportedly suffer from aspiration pneumonia [ 2 ], making it important to understand their swallowing function. A study investigating swallowing function at discharge in older patients with aspiration pneumonia reported 75.9% recovery by Momosaki et al. [ 3 ] and 65.0% by Honda et al. [ 4 ], indicating that swallowing function remained impaired at discharge in many patients. Insufficient recovery of swallowing function at discharge makes it difficult for older patients with pneumonia to return to their previous residence, increases their dependence on medical care, and places a greater burden on caregivers. Furthermore, the nutritional pathway at hospital discharge is associated with life expectancy in older patients with aspiration pneumonia [ 4 ], making it essential to understand factors related to swallowing function during hospitalization and implement therapeutic intervention to prevent its decline. Many factors associated with swallowing function have been reported, including body mass index (BMI) [ 5 ], low body weight [ 6 ], sex [ 6 ], severity of illness [ 6 ], comorbidities [ 6 ], duration of fasting [ 7 ], ADL performance [ 5 , 6 , 8 ], performance status [ 9 ], mobility assistance [ 9 ], malnutrition [ 9 ], decreased nutritional intake [ 9 ], and length of hospital stay [ 9 ]. Among these factors, the relationship between nutritional status and swallowing function has been the focus of attention. A study investigating the relationship between muscle mass and swallowing function found that a decrease in skeletal muscle index [ 5 , 8 ] and the presence of sarcopenia [ 8 ] were associated with swallowing function. Furthermore, a study investigating the relationship between muscle quality and swallowing function found that quadriceps muscle brightness was associated with swallowing function [ 10 ]. For these reasons, it is essential to evaluate skeletal muscles, which are considered important in nutritional status, to understand swallowing function. Recently, methods have been developed to measure the quantity and quality of skeletal muscle using computed tomography (CT) images. In respiratory diseases, associations between parameters obtained from chest CT imaging and prognosis have been reported in conditions such as chronic obstructive pulmonary disease [ 11 ] and idiopathic pulmonary fibrosis [ 12 ]. Recently, we reported that muscle mass rather than muscle quality of the erector spinae muscles (ESM) measured from chest CT images may be associated with short-term life expectancy in older patients with aspiration pneumonia [ 13 ]. In respiratory diseases, chest CT images are often obtained in daily clinical practice to assess disease pathophysiology and can be used to measure skeletal muscle mass and muscle quality. A study investigating the impact of muscle mass and quality measured by chest CT imaging on swallowing function in older hospitalized patients found that skeletal muscle index and intramuscular adipose tissue of the trunk were associated with swallowing function [ 14 ]. These findings suggest that trunk muscle mass and muscle quality may be related to swallowing function; however, it is unclear whether the same trend is observed in older patients with pneumonia. Therefore, the purpose of this study was to clarify the impact of ESM muscle mass and quality, as measured by chest CT imaging, on the decline in swallowing function during hospitalization in older patients with pneumonia. If validated, this study will aid pneumonia treatment by enabling the prediction of swallowing function decline—an essential parameter in older patients with pneumonia—based on parameters measured by chest CT during hospitalization. Methods Study design and participants The study design was a single-center, retrospective, observational study. The participants were patients admitted to Sanuki Municipal Hospital with a diagnosis of pneumonia and underwent pulmonary rehabilitation during the period from April 2018 to March 2024. Exclusion criteria were patients who 1) were younger than 65 years, 2) who died during hospitalization, 3) transferred from other hospitals or during hospitalization, 4) who were bedridden before hospitalization, and 5) with unmeasured or missing chest CT data at the time of admission. The diagnosis of pneumonia at Sanuki Municipal Hospital is based on clinical symptoms (fever, sputum, cough), coarse crackles on auscultation, elevated white blood cell count (WBC) and C-reactive protein (CRP), chest radiographs, and chest CT images. Although participants in this study did not provide written or verbal informed consent, they were allowed to refuse or withdraw from participation at any time. The opt-out procedure conforms to the Japanese Ethical Guidelines for Epidemiological Research for observational studies that use existing data. The study protocol, including the consent procedure (informed consent waiver), was approved by the Ethics Review Board of Hyogo Medical University (approval number: 5058) and conducted in accordance with the principles of the Declaration of Helsinki. Measurements Characteristics of each participant, including age, sex, BMI, Charlson comorbidity Index (CCI), residence location before admission, A-DROP score, mechanical ventilation, intravenous antibiotic administration, WBC, CRP, albumin (Alb), hemoglobin (Hb), Functional Independence Measure (FIM) at the start of pulmonary rehabilitation and at discharge, days to start pulmonary rehabilitation, days to start oral or enteral nutrition, length of hospital stay, residence location after discharge, and rate of change in discharge location, were collected retrospectively from the medical records. Based on previous studies [ 15 ], the CCI included and scored 19 items: myocardial infarction, congestive heart failure, peripheral vascular disease, cerebrovascular disease, dementia, chronic pulmonary disease, connective tissue disease, ulcer disease, mild liver disease, diabetes, hemiplegia, moderate or severe renal disease, diabetes with end organ damage, any tumor, leukemia, lymphoma, moderate or severe liver disease, metastatic solid tumor, and AIDS. The A-DROP score is based on age (male ≥ 70 years, female ≥ 75 years), dehydration (blood urea nitrogen ≥ 21 mg༏dL), respiratory status (peripheral oxygen saturation ≤ 90% or partial pressure of arterial oxygen ≤ 60 mmHg), orientation disturbance, and blood pressure (systolic blood pressure ≤ 90 mmHg) [ 16 ]. The day to start pulmonary rehabilitation was defined as the day when a physical or occupational therapist initiated pulmonary rehabilitation after admission. The day to start oral intake or enteral nutrition was defined as the day on which nutritional management by oral intake or enteral nutrition began. The FIM was calculated by evaluating 13 motor FIM items and 5 cognitive FIM items with 1–7 points each, depending on the amount of assistance, for a total score of 18–126 points for 18 items. Chest CT images taken at admission were used to measure muscle mass and muscle quality. SYNAPSE 5 (Version 5.5, FUJIFILM Medical Co., Ltd., Tokyo, Japan) was used for analysis. The left and right ESMs at the level of the lower 12th thoracic vertebra were measured using the manual trace method, following previous studies [ 17 , 18 ]. The cross-sectional area (CSA) of the left and right ESMs was defined as muscle mass (ESM CSA ), and the CT values of the left and right ESMs as muscle quality (ESM CT ). ESM CSA was adjusted for body surface area (ESM CSA /BSA). ESM CT was calculated by averaging the CT values of the left and right ESMs. Clinical outcomes The Functional Oral Intake Scale (FOIS) was used to determine the clinical outcome of swallowing function [ 19 ]. The FOIS is a standardized seven-level assessment of tube feeding to oral intake developed by Crary et al. The higher the level, the better the swallowing function. FOIS before admission and at discharge was determined by the type of meals the patients consumed at those times. Decline in swallowing function during hospitalization was defined as “a decrease in FOIS at discharge of 2 or more points from the pre-admission FOIS,” based on a previous study [ 7 ]. Statistical analysis First, we calculated the cutoff values, sensitivity, specificity, and area under the curve for ESM CSA /BSA and ESM CT to determine FOIS decline ≥ 2 during hospitalization. The cutoff values were then used to classify the patients into four groups: the High ESM CSA /BSA・ESM CT group, in which both ESM CSA /BSA and ESM CT were high; the Low ESM CSA /BSA group and Low ESM CT group, in which either ESM CSA /BSA or ESM CT was low; and the Low ESM CSA /BSA・ESM CT group, in which both measures were low. The Kruskal–Wallis and χ² tests were used to compare patient characteristics among the four groups. Finally, multiple logistic regression analysis was performed with FOIS decline ≥ 2 as the objective variable; ESM CSA /BSA and ESM CT as explanatory variables; and age, sex, BMI, CCI, A-DROP, mechanical ventilation, intravenous antibiotic administration, pulmonary rehabilitation intervention within 48 hours, and oral intake and enteral nutrition initiation within 48 hours as adjustment variables. Statistical analysis was performed using EZR version 1.68 (Saitama Medical Center, Jichi Medical University, Saitama, Japan) [ 20 ]. The significance level was set at 5% for all analyses. Results Cutoff values for ESM CSA /BSA and ESM CT and distribution of study participants This study included 453 participants out of 1,068 who met the inclusion criteria. Furthermore, 452 participants were analyzed after excluding one individual who had difficulty with oral intake before hospitalization. The cutoff values for ESM CSA /BSA and ESM CT predicting FOIS change ≥ 2 were calculated in the analyzed participants. Consequently, the cutoff value for ESM CSA /BSA was 10.264 cm²/m², and that for ESM CT was 36.020 HU (Fig. 1 ). Based on these cutoff values, the 452 participants were classified into four groups: High ESM CSA /BSA・ESM CT , Low ESM CSA /BSA, Low ESM CT , and Low ESM CSA /BSA・ESM CT (Fig. 2 ). There were 105 patients in the high ESM CSA /BSA・ESM CT group, 87 in the low ESM CSA /BSA group, 146 in the low ESM CT group, and 114 in the low ESM CSA /BSA・ESM CT group. The percentage of patients with both muscle mass and muscle quality decline was 25.2%. Comparison of patient characteristics in each group Table 1 shows the results of the comparison of patient characteristics in each group. In terms of age, the Low ESM CSA /BSA group showed a tendency toward older age. The Low ESM CSA /BSA・ESM CT group had a median age of 88.0 years, and the ESM CSA /BSA・ESM CT group showed a similar tendency with a median age of 87.0 years among the four groups. Regarding A-DROP, which indicates severity, 26 patients (22.9%) in the Low ESM CSA /BSA・ESM CT group were classified as severe or very severe, a proportion higher than that in the other groups. There were no significant differences between the four groups in terms of mechanical ventilation, intravenous antibiotic administration, WBC, and CRP. Regarding ADL performance, both the FIM at the start of pulmonary rehabilitation and the FIM at discharge were significantly lower in the Low ESM CSA /BSA group and the Low ESM CSA /BSA・ESM CT group. Regarding the rate of change in discharge location, the Low ESM CSA /BSA group showed a significantly higher rate of 26.4% compared with the other groups. Furthermore, the length of hospital stay was significantly longer in the Low ESM CSA /BSA group at 26.0 days. Table 1 Comparison of patient characteristics in each group Variables High ESM CSA /BSA・ESM CT Low ESM CSA /BSA Low ESM CT Low ESM CSA /BSA・ESM CT p-value (n = 105) (n = 87) (n = 146) (n = 114) Age years 84.00 [77.00, 89.00] 88.00 [80.50, 92.00] 81.50 [74.25, 87.00] 87.00 [83.00, 91.00] < 0.001 Sex (male) no (%) 65 (61.9) 38 (43.7) 94 (64.4) 58 (50.9) 0.007 BMI kg/m² 20.90 [18.06, 24.14] 20.36 [18.31, 23.61] 20.10 [18.00, 22.67] 20.42 [17.79, 22.72] 0.472 CCI score 2.00 [1.00, 3.00] 2.00 [1.00, 3.00] 2.00 [1.00, 2.75] 2.00 [1.00, 3.00] 0.534 A-DROP score 2.00 [1.00, 2.00] 2.00 [1.00, 2.00] 2.00 [1.00, 2.00] 2.00 [1.00, 2.00] 0.019 mild, no (%) 5 (4.8) 0 (0.0) 14 (9.6) 1 (0.9) 0.012 moderate, no (%) 81 (77.1) 69 (79.3) 109 (74.7) 87 (76.3) severe, no (%) 15 (14.3) 15 (17.2) 17 (11.6) 24 (21.1) very severe, no (%) 4 (3.8) 3 (3.4) 6 (4.1) 2 (1.8) LTCI independent level, no (%) 55 (52.4) 24 (27.6) 82 (56.2) 38 (33.3) < 0.001 support level, no (%) 28 (26.7) 23 (26.4) 36 (24.7) 31 (27.2) care level, no (%) 22 (21.0) 40 (46.0) 28 (19.2) 45 (39.5) Mechanical ventilation no (%) 3 (2.9) 1 (1.1) 1 (0.7) 1 (0.9) 0.469 Intravenous antibiotic administration days 9.00 [7.00, 12.00] 10.00 [7.00, 12.00] 8.50 [7.00, 13.00] 9.00 [6.25, 13.75] 0.563 Oral or EN within 48 hours no (%) 84 (80.0) 68 (78.2) 129 (88.4) 84 (73.7) 0.023 PR within 48 hours no (%) 62 (59.0) 53 (60.9) 84 (57.5) 64 (56.1) 0.914 WBC ×10 2 /µL 103.00 [75.00, 128.00] 101.00 [67.50, 129.50] 95.50 [69.25, 137.50] 103.50 [73.00, 129.75] 0.855 CRP mg/dL 8.99 [2.32, 14.37] 6.14 [2.78, 13.20] 7.60 [2.60, 13.42] 7.05 [2.01, 13.27] 0.692 Alb g/dL 3.49 [3.10, 3.70] 3.30 [2.95, 3.55] 3.26 [2.92, 3.62] 3.26 [2.90, 3.59] 0.014 Hb g/dL 12.00 [11.10, 12.90] 11.20 [10.05, 12.25] 11.65 [10.53, 13.05] 11.35 [10.22, 12.90] 0.028 FIM score at the start of PR points 73.00 [45.00, 93.00] 47.00 [30.50, 69.50] 88.00 [60.25, 103.00] 53.50 [32.00, 80.00] < 0.001 FIM score at discharge points 93.00 [59.00, 111.00] 56.00 [37.00, 90.50] 104.00 [81.00, 116.00] 66.50 [36.00, 97.00] < 0.001 ESM CSA /BSA cm 2 /m 2 13.03 [11.42, 15.10] 7.60 [5.57, 8.86] 13.07 [11.59, 14.98] 7.81 [5.78, 9.23] < 0.001 ESM CT HU 41.86 [39.29, 45.28] 42.41 [40.31, 47.84] 20.85 [10.96, 30.02] 24.95 [11.52, 30.81] < 0.001 Residence location before hospitalization Home, no (%) 77 (73.3) 41 (47.1) 121 (82.9) 64 (56.1) < 0.001 Residence location after hospital discharge Home, no (%) 68 (64.8) 33 (37.9) 111 (76.0) 54 (47.4) < 0.001 Rate of change in discharge location no (%) 14 (13.3) 23 (26.4) 15 (10.3) 18 (15.8) 0.010 Length of hospital stay days 19.00 [11.00, 33.00] 26.00 [15.50, 43.50] 17.00 [11.00, 33.75] 21.00 [13.00, 38.00] 0.041 Data are presented as Median (25th and 75th percentiles) or numbers. Statistical analysis: Kruskal-Wallis test, χ² test Alb: albumin, BMI: body mass index, BSA: body surface area, CCI: Charlson comorbidity index, CRP: C-reactive protein, EN: enteral nutrition, ESM CSA : cross-sectional area of the erector spinae muscles, ESM CT : mean radiographic density of the erector spinae muscles, FIM: functional independence measure, Hb: hemoglobin, HU: Hounsfield unit, LTCI: long term care insurance, PR: pulmonary rehabilitation, WBC: white blood cell Comparison of FOIS before hospitalization and at discharge in each group Table 2 presents the comparison of FOIS scores before hospitalization and at discharge for each group. In the High ESM CSA /BSA・ESM CT and Low ESM CT groups, FOIS decreased from Level 7 to Level 6, whereas in the Low ESM CSA /BSA and Low ESM CSA /BSA・ESM CT groups, FOIS decreased from Level 7 to Level 5, indicating a greater change. In addition, among patients who switched to tube feeding owing to difficulty with oral intake, the Low ESM CSA /BSA group had the highest number of cases (9 cases, 10.3%) compared with the other groups. Table 2 Comparison of pre-admission and discharge FOIS in each group Variables High ESM CSA /BSA・ESM CT Low ESM CSA /BSA Low ESM CT Low ESM CSA /BSA・ESM CT p-value (n = 105) (n = 87) (n = 146) (n = 114) FOIS score before hospitalization score 7.00 [7.00, 7.00] 7.00 [6.00, 7.00] 7.00 [7.00, 7.00] 7.00 [6.00, 7.00] 0.019 Level.1 0 (0.0) 0 (0.0) 0 (0.0) 0 (0.0) 0.189 Level.2 0 (0.0) 0 (0.0) 0 (0.0) 0 (0.0) Level.3 0 (0.0) 1 (1.1) 0 (0.0) 1 (0.9) Level.4 2 (1.9) 5 (5.7) 7 (4.8) 4 (3.5) Level.5 10 (9.5) 14 (16.1) 10 (6.8) 20 (17.5) Level.6 14 (13.3) 12 (13.8) 15 (10.3) 15 (13.2) Level.7 79 (75.2) 55 (63.2) 114 (78.1) 74 (64.9) FOIS score at discharge score 6.00 [5.00, 6.00] 5.00 [4.00, 6.00] 6.00 [5.00, 6.00] 5.00 [5.00, 6.00] < 0.001 Level.1 5 (4.8) 9 (10.3) 4 (2.7) 8 (7.0) 0.001 Level.2 0 (0.0) 2 (2.3) 1 (0.7) 1 (0.9) Level.3 0 (0.0) 0 (0.0) 0 (0.0) 1 (0.9) Level.4 13 (12.4) 17 (19.5) 10 (6.8) 13 (11.4) Level.5 24 (22.9) 32 (36.8) 38 (26.0) 42 (36.8) Level.6 44 (41.9) 22 (25.3) 62 (42.5) 40 (35.1) Level.7 19 (18.1) 5 (5.7) 31 (21.2) 9 (7.9) Data are presented as Median (25th and 75th percentiles) or numbers. Statistical analysis: Kruskal–Wallis test, χ² test BSA: body surface area, ESM CSA : cross-sectional area of the erector spinae muscles, ESM CT : mean radiographic density of the erector spinae muscles, FOIS: functional oral intake scale Correlation between ESM CSA /BSA and ESM CT and FOIS change Table 3 presents the results of multiple logistic regression analysis with FOIS change ≥ 2 as the objective variable. In univariate analysis, FOIS change and Low ESM CSA /BSA were significantly associated (OR: 1.94, 95% CI: 1.07–3.51, p = 0.028). Low ESM CT and Low ESM CSA /BSA・ESM CT showed no significant correlation. After adjusting for age, sex, BMI, CCI, A-DROP, mechanical ventilation, intravenous antibiotic administration, initiation of pulmonary rehabilitation within 48 hours, and initiation of oral intake or enteral nutrition within 48 hours, multivariate analysis revealed that Low ESM CSA /BSA was significantly associated with FOIS change (OR: 1.97, 95% CI: 1.05–3.69, p = 0.035). Table 3 Relationship between muscle mass and muscle quality of erector spinae muscles and FOIS changes Unadjusted model Adjusted model OR (95% CI) p-value OR (95% CI) p-value High ESM CSA /BSAཥESM CT 1.00 (Reference) 1.00 (Reference) Low ESM CSA /BSA 1.94 (1.07–3.51) 0.028 1.97 (1.05–3.69) 0.035 Low ESM CT 0.64 (0.36–1.13) 0.126 0.71 (0.39–1.28) 0.253 Low ESM CSA /BSAཥESM CT 1.23 (0.70–2.17) 0.468 1.15 (0.63–2.10) 0.648 Statistical analysis: multiple logistic regression analysis. OR: odds ratio, 95% CI: 95% confidence interval. Adjusted models included age, sex, BMI, CCI, A-DROP, mechanical ventilation, intravenous antibiotic administration, PR within 48 hours, and oral or enteral nutrition within 48 hours. Cutoff value for ESM CSA /BSA: 10.264 cm 2 /m 2 Cutoff value for ESM CT : 36.020 HU BMI: body mass index, BSA: body surface area, CCI: Charlson comorbidity index, ESM CSA : cross-sectional area of the erector spinae muscles, ESM CT : mean radiographic density of the erector spinae muscles, FOIS: functional oral intake scale, PR: pulmonary rehabilitation Discussion In this study, we examined the relationship between swallowing dysfunction during hospitalization in older patients with pneumonia and muscle mass (ESM CSA /BSA) and muscle quality (ESM CT ) measured using chest CT images. The findings showed that changes in FOIS during hospitalization in older patients with pneumonia were significantly greater in cases of Low ESM CSA /BSA, which reflects reduced muscle mass, and Low ESM CSA /BSA・ESMCT, indicating a decrease in both muscle mass and muscle quality, with Low ESM CSA /BSA having the strongest influence. Based on these findings, this study is the first to demonstrate a correlation between swallowing dysfunction during hospitalization and muscle mass measured by chest CT imaging in older patients with pneumonia. These findings support the importance of identifying factors that can predict swallowing dysfunction without additional testing by relying on chest CT images, which are often obtained in older patients with pneumonia. Recently, attention has been focused on the relationship between sarcopenia and swallowing function. Previous studies [ 5 , 8 , 21 ] have also shown that sarcopenia is independently associated with dysphagia. A position paper on sarcopenia and dysphagia published in 2019 also includes “systemic skeletal muscle loss” in its diagnostic algorithm, indicating that skeletal muscle loss is an important factor in dysphagia [ 22 ]. The ESMs examined in this study have several roles that are believed to contribute to physical function. First, the ESM is related to respiratory function. The ESM is one of the important respiratory accessory muscles, and previous studies have shown that ESM muscle mass measured using chest CT images is associated with respiratory function, such as forced expiratory volume in one second and vital capacity [ 11 ]. Furthermore, respiratory function is significantly associated with cough strength, which is considered important in preventing pneumonia [ 23 ], and individuals who developed aspiration pneumonia had significantly reduced cough strength [ 24 ]. There is also a close relationship between swallowing and respiratory function. A study of patients with chronic obstructive pulmonary disease reported a significant association between respiratory-swallowing dyssynchrony and respiratory function and the frequency of acute exacerbations [ 25 ]. These findings suggest that reduced ESM muscle mass may affect swallowing function through its impact on declining respiratory function. Secondly, the ESM is related to posture control. Swallowing and posture are closely related, and among the pathological background diseases leading to asymptomatic or overt aspiration, age-related skeletal changes, such as kyphosis and scoliosis, are also described [ 26 ]. The ESM is one of the critical postural muscles, and a decrease in the cross-sectional area and density of the thoracic trunk muscles is significantly associated with thoracic kyphosis [ 27 ]. Furthermore, trunk muscle mass has been reported to be significantly correlated with swallowing-related muscle mass [ 28 ]. Previous studies have reported a 31% prevalence of dysphagia among patients with sarcopenia [ 29 ]. Sarcopenia has been reported to be significantly associated with the development of dysphagia during hospitalization [ 9 , 30 ]. Therefore, decreased ESM muscle mass measured by CT in this study may be associated with a decline in swallowing function during hospitalization. Although a decrease in trunk muscle mass does not directly affect swallowing function, it can indirectly create unfavorable conditions for swallowing, which may contribute to the onset of aspiration pneumonia. However, in this study, ESM CT , an indicator of muscle quality, was not associated with swallowing dysfunction either alone or in combination, which differs from previous findings [ 10 , 14 ]. This finding may be due to the conditions and characteristics of the skeletal muscles measured. The ESM is generally considered to have a higher distribution of Type I fibers than Type II fibers [ 31 ], which is thought to favor muscle endurance rather than muscle strength. In a study by Akazawa et al. [ 10 ], the target muscle was the quadriceps femoris, which has a higher distribution of Type II fibers that favor muscle strength rather than muscle endurance, and this characteristic was considered to have a high correlation with the strength of the swallowing muscles. In a study by Jing et al. [ 14 ], muscle mass was measured at the level of the 12th thoracic vertebra, as in this study, but the difference between their findings and ours was likely due to their measurement of muscles other than the ESMs. In the future, it will be necessary to examine the effects of muscle quality on swallowing dysfunction in older patients with pneumonia, including muscles other than the ESM. Based on the above, evaluating muscle mass reduction in older patients with pneumonia using ESM may be an essential factor in predicting future swallowing dysfunction. This study has some limitations. First, this is a single-center study, and there are concerns regarding the applicability of the results to other facilities. Therefore, it will be necessary to explore its application in clinical settings through multi-facility collaborative research. Second, in this study, the relationship between muscle mass reduction and muscle quality deterioration in muscles involved in swallowing, which are thought to be directly related to swallowing function, remains unclear. In the future, it will be necessary to use ultrasound to measure the muscle mass and muscle quality of the muscles involved in swallowing and examine their correlation. Third, this study examined muscle mass and muscle quality at a single time point during hospitalization and did not assess skeletal muscle changes after hospitalization. Previous studies have shown that muscle mass measured by ESM on chest CT images decreases during treatment in older patients with aspiration pneumonia [ 32 ]. Further study is needed to determine whether such longitudinal changes in ESM muscle mass and muscle quality are associated with clinical outcomes. Fourth, this study focused on the ESM but did not examine other muscles. Therefore, it is necessary to examine other muscles as indicators to determine whether the results of this study apply to muscles beyond the ESM or whether they are specific to the ESM. Conclusions The results of this study suggest that muscle mass measurement using chest CT images is strongly associated with a decline in swallowing function during hospitalization in older patients with pneumonia. Therefore, evaluating skeletal muscles using chest CT images, which are commonly obtained during the treatment of pneumonia in older patients, is feasible in daily clinical practice and provides important information for predicting decline in swallowing function. Abbreviations Alb albumin BMI body mass index BSA body surface area CCI Charlson comorbidity index CI confidence interval CRP c-reactive protein CT computed tomography EN enteral nutrition ESM erector spinae muscles ESM CSA cross-sectional area of the erector spinae muscles ESM CT mean radiographic density of the erector spinae muscles FIM functional independence measure FOIS functional oral intake scale Hb hemoglobin HU hounsfield unit LTCI long term care insurance OR odds ratio PR pulmonary rehabilitation ROC receiver operating characteristic WBC white blood cell Declarations Acknowledgment We thank the Department of Internal Medicine and the Department of Rehabilitation Technology at Sanuki Municipal Hospital for their cooperation in data collection. We would like to thank Editage (www.editage.jp) for English language editing. Author contributions Y uichi Murakawa : Writing – original draft, Validation, Resources, Methodology, Investigation, Formal analysis, Data curation, Conceptualization. A kira T amaki : Writing – review & editing, Supervision, Project administration, Methodology, Investigation, Formal analysis, Conceptualization. R yota M atsuzawa : Writing – review & editing, Methodology, Investigation, Formal analysis. S hinjiro M iyazaki : Writing – review & editing, Methodology, Investigation. K oji F ujishima : Methodology, Formal analysis, Data curation. T atsuma H ori : Methodology, Formal analysis, Data curation. M iki N aide : Methodology, Formal analysis, Data curation. K enichiro S akai : Writing – review & editing, Methodology, Investigation, Formal analysis, Data curation. T omoya I shii : Writing – review & editing, Methodology, Investigation, Formal analysis, Data curation. Funding The authors did not receive support from any organization for the submitted work. Data availability statement The data collected/analyzed by the current study have not been released to the public for privacy reasons. If there is a reasonable request, we will consider submitting the data. Ethics approval and consent to participate Although participants in this study did not provide written or verbal informed consent, they were allowed to refuse or withdraw from participation at any time. The opt-out procedure conforms to the Japanese Ethical Guidelines for Epidemiological Research for observational studies that use existing data. The study protocol, including the consent procedure (informed consent waiver), was approved by the Ethics Review Board of Hyogo Medical University (approval number: 5058) and conducted in accordance with the principles of the Declaration of Helsinki. Consent for publication Not applicable. Competing interest There is no conflict of interest. Clinical trial number Not applicable. Author details 1 Graduate School of Rehabilitation Science, Hyogo Medical University, 1-3-6 Minatojima, Chuo Ward, Kobe, Hyogo 650-8530 Japan 2 Department of Rehabilitation Technology, Sanuki Municipal Hospital, 387-1 Ishida Higashi Kou, Sangawa-cho, Sanuki City, Kagawa 769-2393 Japan 3 Rehabilitation Center, KKR Takamatsu Hospital, 4-18 Tenjinmae, Takamatsu City, Kagawa 760-0018, Japan 4 Department of Respiratory Medicine, Sanuki Municipal Hospital, 387-1 Ishida Higashi Kou, Sangawa-cho, Sanuki City, Kagawa 769-2393 Japan References Morimoto K, Suzuki M, Ishifuji T, et al. The burden and etiology of community-onset pneumonia in the aging Japanese population: a multicenter prospective study. PLoS One. 2015;10(3):e0122247. https://doi.org/10.1371/journal.pone.0122247. Teramoto S, Fukuchi Y, Sasaki H, et al. High incidence of aspiration pneumonia in community- and hospital-acquired pneumonia in hospitalized patients: a multicenter, prospective study in Japan. J Am Geriatr Soc. 2008;56(3):577-9. https://doi.org/10.1111/j.1532-5415.2008.01597.x. Momosaki R, Yasunaga H, Matsui H, et al. Effect of dysphagia rehabilitation on oral intake in elderly patients with aspiration pneumonia. Geriatr Gerontol Int. 2015;15(6):694-9. https://doi.org/10.1111/ggi.12333. Honda Y, Homma Y, Nakamura M, et al. Extremely Poor Post-discharge Prognosis in Aspiration Pneumonia and Its Prognostic Factors: A Retrospective Cohort Study. Dysphagia. 2024;39(5):837-845. https://doi.org/10.1007/s00455-023-10665-z. Maeda K, Takaki M, Akagi J. Decreased Skeletal Muscle Mass and Risk Factors of Sarcopenic Dysphagia: A Prospective Observational Cohort Study. J Gerontol A Biol Sci Med Sci. 2017;72(9):1290-1294. https://doi.org/10.1093/gerona/glw190. Momosaki R, Yasunaga H, Matsui H, et al. Predictive factors for oral intake after aspiration pneumonia in older adults. Geriatr Gerontol Int. 2016;16(5):556-60. https://doi.org/10.1111/ggi.12506. Maeda K, Koga T, Akagi J. Tentative nil per os leads to poor outcomes in older adults with aspiration pneumonia. Clin Nutr. 2016;35(5):1147-52. https://doi.org/10.1016/j.clnu.2015.09.011. Maeda K, Akagi J. Sarcopenia is an independent risk factor of dysphagia in hospitalized older people. Geriatr Gerontol Int. 2016;16(4):515-21. https://doi.org/10.1111/ggi.12486. Maeda K, Ishida Y, Nonogaki T, et al. Development and Predictors of Sarcopenic Dysphagia during Hospitalization of Older Adults. Nutrients. 2019;12(1):70. https://doi.org/10.3390/nu12010070. Akazawa N, Okawa N, Hino T, et al. Dysphagia is more strongly associated with increased intramuscular adipose tissue of the quadriceps than with loss of muscle mass in older inpatients. Nutr Res. 2019;65:71-78. https://doi.org/10.1016/j.nutres.2019.02.006. Tanimura K, Sato S, Fuseya Y, et al. Quantitative Assessment of Erector Spinae Muscles in Patients with Chronic Obstructive Pulmonary Disease. Novel Chest Computed Tomography-derived Index for Prognosis. Ann Am Thorac Soc. 2016;13(3):334-41. https://doi.org/10.1513/AnnalsATS.201507-446OC. Awano N, Inomata M, Kuse N, et al. Quantitative computed tomography measures of skeletal muscle mass in patients with idiopathic pulmonary fibrosis according to a multidisciplinary discussion diagnosis: A retrospective nationwide study in Japan. Respir Investig. 2020;58(2):91-101. https://doi.org/10.1016/j.resinv.2019.11.002. Murakawa Y, Tamaki A, Matsuzawa R, et al. Impact of the quantity and quality of erector spinae muscles on the short-term prognosis of elderly patients with aspiration pneumonia in Japan. Respir Med. 2024;232:107746. https://doi.org/10.1016/j.rmed.2024.107746. Jing X, Yang M, Liu Y, et al. Associations of Trunk Muscle Mass and Muscle Quality Indicators with Self-Reported Dysphagia in Older Inpatients. Dysphagia. 2023;38(1):415-424. https://doi.org/10.1007/s00455-022-10480-y. Charlson M.E, Pompei P, Ales K.L, et al. A new method of classifying prognostic comorbidity in longitudinal studies: development and validation. J Chronic Dis. 1987;40(5):373-83. https://doi.org/10.1016/0021-9681(87)90171-8. Shindo Y, Sato S, Maruyama E, et al. Comparison of severity scoring systems A-DROP and CURB-65 for community-acquired pneumonia. Respirology. 2008;13(5):731-5. https://doi.org/10.1111/j.1440-1843.2008.01329.x. Minegishi Y, Inoue S, Sato K, et al. Smaller erector spinae muscle size is associated with inability to recover activities of daily living after pneumonia treatment. Respir Investig. 2019;57(2):191-197. https://doi.org/10.1016/j.resinv.2018.11.002. Oshima Y, Sato S, Chen-Yoshikawa T.F, et al. Quantity and quality of antigravity muscles in patients undergoing living-donor lobar lung transplantation: 1-year longitudinal analysis using chest computed tomography images. ERJ Open Res. 2020;6(2):00205-2019. https://doi.org/10.1183/23120541.00205-2019. Crary M.A, Mann G.D, Groher M.E. Initial psychometric assessment of a functional oral intake scale for dysphagia in stroke patients. Arch Phys Med Rehabil. 2005;86(8):1516-20. https://doi.org/10.1016/j.apmr.2004.11.049. Kanda Y. Investigation of the freely available easy-to-use software 'EZR' for medical statistics. Bone Marrow Transplant. 2013;48(3):452-8. https://doi.org/10.1038/bmt.2012.244. Cha S, Kim W.S, Kim K.W, et al. Sarcopenia is an Independent Risk Factor for Dysphagia in Community-Dwelling Older Adults. Dysphagia. 2019;34(5):692-697. https://doi.org/10.1007/s00455-018-09973-6. Fujishima I, Fujiu-Kurachi M, Arai H, et al. Sarcopenia and dysphagia: Position paper by four professional organizations. Geriatr Gerontol Int. 2019;19(2):91-97. https://doi.org/10.1111/ggi.13591. Gauld L.M, Boynton A. Relationship between peak cough flow and spirometry in Duchenne muscular dystrophy. Pediatr Pulmonol. 2005;39(5):457-60. https://doi.org/10.1002/ppul.20151. Sohn D, Park G.Y, Koo H, et al. Determining Peak Cough Flow Cutoff Values to Predict Aspiration Pneumonia Among Patients With Dysphagia Using the Citric Acid Reflexive Cough Test. Arch Phys Med Rehabil. 2018;99(12):2532-2539.e1. https://doi.org/10.1016/j.apmr.2018.06.015. Nagami S, Oku Y, Yagi N, et al. Breathing-swallowing discoordination is associated with frequent exacerbations of COPD. BMJ Open Respir Res. 2017;4(1):000202. https://doi.org/10.1136/bmjresp-2017-000202. Teramoto S. The current definition, epidemiology, animal models and a novel therapeutic strategy for aspiration pneumonia. Respir Investig. 2022;60(1):45-55. https://doi.org/10.1016/j.resinv.2021.09.012. Lorbergs A.L, Allaire B.T, Yang L, et al. A Longitudinal Study of Trunk Muscle Properties and Severity of Thoracic Kyphosis in Women and Men: The Framingham Study. J Gerontol A Biol Sci Med Sci. 2019;74(3):420-427. https://doi.org/10.1093/gerona/gly056. Yamaguchi K, Nakagawa K, Yoshimi K, et al. Association between characteristics of swallowing-related muscles and trunk muscle mass. Sci Rep. 2023;13(1):7814. https://doi.org/10.1038/s41598-023-34905-2. Li Y, Li J, Xian L, et al. Prevalence and Risk Factors of Dysphagia in Patients with Sarcopenia: A Meta-Analysis. Dysphagia. 2026;41(1):218-228. https://doi.org/10.1007/s00455-025-10872-w. Yoshimura Y, Wakabayashi H, Bise T, et al. Sarcopenia is associated with worse recovery of physical function and dysphagia and a lower rate of home discharge in Japanese hospitalized adults undergoing convalescent rehabilitation. Nutrition. 2019;61:111-118. https://doi.org/10.1016/j.nut.2018.11.005. Johnson M.A, Polgar J, Weightman D, et al. (1973) Data on the distribution of fibre types in thirty-six human muscles. An autopsy study. J Neurol Sci. 1973;18(1):111-29. https://doi.org/10.1016/0022-510x(73)90023-3. Komatsu R, Okazaki T, Ebihara S, et al. Aspiration pneumonia induces muscle atrophy in the respiratory, skeletal, and swallowing systems. J Cachexia Sarcopenia Muscle. 2018;9(4):643-653. https://doi.org/10.1002/jcsm.12297. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-9201548","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":620242749,"identity":"859912fc-ca9d-45e6-8d72-0363bb510baa","order_by":0,"name":"Yuichi Murakawa","email":"","orcid":"","institution":"Hyogo Medical University","correspondingAuthor":false,"prefix":"","firstName":"Yuichi","middleName":"","lastName":"Murakawa","suffix":""},{"id":620242750,"identity":"a0234feb-984e-467b-91c2-853f1e283f8c","order_by":1,"name":"Akira Tamaki","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA/ElEQVRIiWNgGAWjYPCCBB5+CQiLsQFESuBVzQzRIjmDVC0MBjeQteAD/A38Bz/dqEmTMb7dY/iAMcdGtoH98AMGyx24tUgcYGaWzjmWw2N254yxAeO2NOMGnjQDBskzeKy5/5hBOoetgsfsRo6Z9N9thxMbGHIYGCTbcOuQB9ryO+dfBY/xjBwzCcZt/xMb+N/g12JwgJlNOrcth8dAAqzlQGKDBAFbDA8wm1nn9qXxSNxIKwb6Jdm4TeKZwQF8fpE7wPj4ds63ZHv+GckbHzBus5Pt509++FgST4ghAQ4DMMUGxIclG4jSwv4AzmT8SJyWUTAKRsEoGBkAAHT7SogIOXxbAAAAAElFTkSuQmCC","orcid":"","institution":"Hyogo Medical University","correspondingAuthor":true,"prefix":"","firstName":"Akira","middleName":"","lastName":"Tamaki","suffix":""},{"id":620242751,"identity":"12e2ddc6-ec83-4b4f-9701-d75277de53e9","order_by":2,"name":"Ryota Matsuzawa","email":"","orcid":"","institution":"Hyogo Medical University","correspondingAuthor":false,"prefix":"","firstName":"Ryota","middleName":"","lastName":"Matsuzawa","suffix":""},{"id":620242752,"identity":"b51d4e6f-315f-44c1-9f0d-08bf98b8574c","order_by":3,"name":"Shinjiro Miyazaki","email":"","orcid":"","institution":"KKR Takamatsu Hospital","correspondingAuthor":false,"prefix":"","firstName":"Shinjiro","middleName":"","lastName":"Miyazaki","suffix":""},{"id":620242754,"identity":"e394dbb7-5041-462a-8cf0-ea69fd8460d6","order_by":4,"name":"Koji Fujishima","email":"","orcid":"","institution":"Sanuki Municipal Hospital","correspondingAuthor":false,"prefix":"","firstName":"Koji","middleName":"","lastName":"Fujishima","suffix":""},{"id":620242757,"identity":"db9c7f3c-2860-438a-ad5c-80171325861d","order_by":5,"name":"Tatsuma Hori","email":"","orcid":"","institution":"Sanuki Municipal Hospital","correspondingAuthor":false,"prefix":"","firstName":"Tatsuma","middleName":"","lastName":"Hori","suffix":""},{"id":620242760,"identity":"702efe92-31b2-488c-9786-1953a482f666","order_by":6,"name":"Miki Naide","email":"","orcid":"","institution":"Sanuki Municipal Hospital","correspondingAuthor":false,"prefix":"","firstName":"Miki","middleName":"","lastName":"Naide","suffix":""},{"id":620242761,"identity":"3b106fef-005f-4eba-b3f3-ce366293f04c","order_by":7,"name":"Kenichiro Sakai","email":"","orcid":"","institution":"Sanuki Municipal Hospital","correspondingAuthor":false,"prefix":"","firstName":"Kenichiro","middleName":"","lastName":"Sakai","suffix":""},{"id":620242762,"identity":"d4ae06cf-e36d-4af0-aa2a-443687e3a5a8","order_by":8,"name":"Tomoya Ishii","email":"","orcid":"","institution":"Sanuki Municipal Hospital","correspondingAuthor":false,"prefix":"","firstName":"Tomoya","middleName":"","lastName":"Ishii","suffix":""}],"badges":[],"createdAt":"2026-03-23 14:08:05","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9201548/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9201548/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":106635764,"identity":"bcbae74e-0273-4b0b-979f-9cd9358565d6","added_by":"auto","created_at":"2026-04-10 16:50:12","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":104918,"visible":true,"origin":"","legend":"\u003cp\u003eROC curves for ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA and ESM\u003csub\u003eCT\u003c/sub\u003e predicting FOIS change ≥ 2 in older patients with pneumonia. The cutoff values were 10.264 cm²/m² for ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA and 36.020 HU for ESM\u003csub\u003eCT\u003c/sub\u003e. AUC, area under the curve; BSA, body surface area; CI, confidence interval; ESM\u003csub\u003eCSA\u003c/sub\u003e, cross-sectional area of the erector spinae muscles; ESM\u003csub\u003eCT\u003c/sub\u003e, mean radiographic density of the erector spinae muscles; FOIS, functional oral intake scale; HU, Hounsfield unit; ROC, receiver operating characteristic\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-9201548/v1/0f746c3ba29c9e244fd68deb.png"},{"id":106635765,"identity":"a0944fdc-c608-4802-8d5f-1d0dc2b65785","added_by":"auto","created_at":"2026-04-10 16:50:12","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":90695,"visible":true,"origin":"","legend":"\u003cp\u003eFlow chart of the inclusion of study subjects and the number of patients included in each group\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-9201548/v1/36402c618d554fe45ba4234f.png"},{"id":109081007,"identity":"ceb9b4dd-1b02-4511-82d1-cb969c4b3153","added_by":"auto","created_at":"2026-05-12 11:48:11","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":673912,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9201548/v1/e252a024-8a76-4e4f-a347-cc5ff3ac981d.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Impact of erector spinae muscle mass and quality on decline in swallowing function during hospitalization in older patients with pneumonia: single-center retrospective observational study in Japan","fulltext":[{"header":"Introduction","content":"\u003cp\u003eRecently, Japan's population has been aging more rapidly than that of other countries. There is a close relationship between the aging of the population and the incidence of pneumonia [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Many older patients with pneumonia reportedly suffer from aspiration pneumonia [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e], making it important to understand their swallowing function.\u003c/p\u003e \u003cp\u003eA study investigating swallowing function at discharge in older patients with aspiration pneumonia reported 75.9% recovery by Momosaki et al. [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e] and 65.0% by Honda et al. [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e], indicating that swallowing function remained impaired at discharge in many patients. Insufficient recovery of swallowing function at discharge makes it difficult for older patients with pneumonia to return to their previous residence, increases their dependence on medical care, and places a greater burden on caregivers. Furthermore, the nutritional pathway at hospital discharge is associated with life expectancy in older patients with aspiration pneumonia [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e], making it essential to understand factors related to swallowing function during hospitalization and implement therapeutic intervention to prevent its decline.\u003c/p\u003e \u003cp\u003eMany factors associated with swallowing function have been reported, including body mass index (BMI) [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e], low body weight [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e], sex [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e], severity of illness [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e], comorbidities [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e], duration of fasting [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e], ADL performance [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e], performance status [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e], mobility assistance [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e], malnutrition [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e], decreased nutritional intake [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e], and length of hospital stay [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eAmong these factors, the relationship between nutritional status and swallowing function has been the focus of attention. A study investigating the relationship between muscle mass and swallowing function found that a decrease in skeletal muscle index [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e] and the presence of sarcopenia [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e] were associated with swallowing function. Furthermore, a study investigating the relationship between muscle quality and swallowing function found that quadriceps muscle brightness was associated with swallowing function [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. For these reasons, it is essential to evaluate skeletal muscles, which are considered important in nutritional status, to understand swallowing function. Recently, methods have been developed to measure the quantity and quality of skeletal muscle using computed tomography (CT) images. In respiratory diseases, associations between parameters obtained from chest CT imaging and prognosis have been reported in conditions such as chronic obstructive pulmonary disease [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e] and idiopathic pulmonary fibrosis [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Recently, we reported that muscle mass rather than muscle quality of the erector spinae muscles (ESM) measured from chest CT images may be associated with short-term life expectancy in older patients with aspiration pneumonia [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. In respiratory diseases, chest CT images are often obtained in daily clinical practice to assess disease pathophysiology and can be used to measure skeletal muscle mass and muscle quality.\u003c/p\u003e \u003cp\u003eA study investigating the impact of muscle mass and quality measured by chest CT imaging on swallowing function in older hospitalized patients found that skeletal muscle index and intramuscular adipose tissue of the trunk were associated with swallowing function [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. These findings suggest that trunk muscle mass and muscle quality may be related to swallowing function; however, it is unclear whether the same trend is observed in older patients with pneumonia.\u003c/p\u003e \u003cp\u003eTherefore, the purpose of this study was to clarify the impact of ESM muscle mass and quality, as measured by chest CT imaging, on the decline in swallowing function during hospitalization in older patients with pneumonia. If validated, this study will aid pneumonia treatment by enabling the prediction of swallowing function decline\u0026mdash;an essential parameter in older patients with pneumonia\u0026mdash;based on parameters measured by chest CT during hospitalization.\u003c/p\u003e"},{"header":"Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStudy design and participants\u003c/h2\u003e \u003cp\u003eThe study design was a single-center, retrospective, observational study. The participants were patients admitted to Sanuki Municipal Hospital with a diagnosis of pneumonia and underwent pulmonary rehabilitation during the period from April 2018 to March 2024. Exclusion criteria were patients who 1) were younger than 65 years, 2) who died during hospitalization, 3) transferred from other hospitals or during hospitalization, 4) who were bedridden before hospitalization, and 5) with unmeasured or missing chest CT data at the time of admission. The diagnosis of pneumonia at Sanuki Municipal Hospital is based on clinical symptoms (fever, sputum, cough), coarse crackles on auscultation, elevated white blood cell count (WBC) and C-reactive protein (CRP), chest radiographs, and chest CT images.\u003c/p\u003e \u003cp\u003e Although participants in this study did not provide written or verbal informed consent, they were allowed to refuse or withdraw from participation at any time. The opt-out procedure conforms to the Japanese Ethical Guidelines for Epidemiological Research for observational studies that use existing data. The study protocol, including the consent procedure (informed consent waiver), was approved by the Ethics Review Board of Hyogo Medical University (approval number: 5058) and conducted in accordance with the principles of the Declaration of Helsinki.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eMeasurements\u003c/h3\u003e\n\u003cp\u003eCharacteristics of each participant, including age, sex, BMI, Charlson comorbidity Index (CCI), residence location before admission, A-DROP score, mechanical ventilation, intravenous antibiotic administration, WBC, CRP, albumin (Alb), hemoglobin (Hb), Functional Independence Measure (FIM) at the start of pulmonary rehabilitation and at discharge, days to start pulmonary rehabilitation, days to start oral or enteral nutrition, length of hospital stay, residence location after discharge, and rate of change in discharge location, were collected retrospectively from the medical records. Based on previous studies [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e], the CCI included and scored 19 items: myocardial infarction, congestive heart failure, peripheral vascular disease, cerebrovascular disease, dementia, chronic pulmonary disease, connective tissue disease, ulcer disease, mild liver disease, diabetes, hemiplegia, moderate or severe renal disease, diabetes with end organ damage, any tumor, leukemia, lymphoma, moderate or severe liver disease, metastatic solid tumor, and AIDS. The A-DROP score is based on age (male\u0026thinsp;\u0026ge;\u0026thinsp;70 years, female\u0026thinsp;\u0026ge;\u0026thinsp;75 years), dehydration (blood urea nitrogen\u0026thinsp;\u0026ge;\u0026thinsp;21 mg༏dL), respiratory status (peripheral oxygen saturation\u0026thinsp;\u0026le;\u0026thinsp;90% or partial pressure of arterial oxygen\u0026thinsp;\u0026le;\u0026thinsp;60 mmHg), orientation disturbance, and blood pressure (systolic blood pressure\u0026thinsp;\u0026le;\u0026thinsp;90 mmHg) [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. The day to start pulmonary rehabilitation was defined as the day when a physical or occupational therapist initiated pulmonary rehabilitation after admission. The day to start oral intake or enteral nutrition was defined as the day on which nutritional management by oral intake or enteral nutrition began. The FIM was calculated by evaluating 13 motor FIM items and 5 cognitive FIM items with 1\u0026ndash;7 points each, depending on the amount of assistance, for a total score of 18\u0026ndash;126 points for 18 items.\u003c/p\u003e \u003cp\u003eChest CT images taken at admission were used to measure muscle mass and muscle quality. SYNAPSE 5 (Version 5.5, FUJIFILM Medical Co., Ltd., Tokyo, Japan) was used for analysis. The left and right ESMs at the level of the lower 12th thoracic vertebra were measured using the manual trace method, following previous studies [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. The cross-sectional area (CSA) of the left and right ESMs was defined as muscle mass (ESM\u003csub\u003eCSA\u003c/sub\u003e), and the CT values of the left and right ESMs as muscle quality (ESM\u003csub\u003eCT\u003c/sub\u003e). ESM\u003csub\u003eCSA\u003c/sub\u003e was adjusted for body surface area (ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA). ESM\u003csub\u003eCT\u003c/sub\u003e was calculated by averaging the CT values of the left and right ESMs.\u003c/p\u003e\n\u003ch3\u003eClinical outcomes\u003c/h3\u003e\n\u003cp\u003eThe Functional Oral Intake Scale (FOIS) was used to determine the clinical outcome of swallowing function [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. The FOIS is a standardized seven-level assessment of tube feeding to oral intake developed by Crary et al. The higher the level, the better the swallowing function. FOIS before admission and at discharge was determined by the type of meals the patients consumed at those times. Decline in swallowing function during hospitalization was defined as \u0026ldquo;a decrease in FOIS at discharge of 2 or more points from the pre-admission FOIS,\u0026rdquo; based on a previous study [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e].\u003c/p\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analysis\u003c/h2\u003e \u003cp\u003eFirst, we calculated the cutoff values, sensitivity, specificity, and area under the curve for ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA and ESM\u003csub\u003eCT\u003c/sub\u003e to determine FOIS decline\u0026thinsp;\u0026ge;\u0026thinsp;2 during hospitalization. The cutoff values were then used to classify the patients into four groups: the High ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA・ESM\u003csub\u003eCT\u003c/sub\u003e group, in which both ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA and ESM\u003csub\u003eCT\u003c/sub\u003e were high; the Low ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA group and Low ESM\u003csub\u003eCT\u003c/sub\u003e group, in which either ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA or ESM\u003csub\u003eCT\u003c/sub\u003e was low; and the Low ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA・ESM\u003csub\u003eCT\u003c/sub\u003e group, in which both measures were low. The Kruskal\u0026ndash;Wallis and χ\u0026sup2; tests were used to compare patient characteristics among the four groups. Finally, multiple logistic regression analysis was performed with FOIS decline\u0026thinsp;\u0026ge;\u0026thinsp;2 as the objective variable; ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA and ESM\u003csub\u003eCT\u003c/sub\u003e as explanatory variables; and age, sex, BMI, CCI, A-DROP, mechanical ventilation, intravenous antibiotic administration, pulmonary rehabilitation intervention within 48 hours, and oral intake and enteral nutrition initiation within 48 hours as adjustment variables. Statistical analysis was performed using EZR version 1.68 (Saitama Medical Center, Jichi Medical University, Saitama, Japan) [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. The significance level was set at 5% for all analyses.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eCutoff values for ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA and ESM\u003csub\u003eCT\u003c/sub\u003e and distribution of study participants\u003c/h2\u003e \u003cp\u003eThis study included 453 participants out of 1,068 who met the inclusion criteria. Furthermore, 452 participants were analyzed after excluding one individual who had difficulty with oral intake before hospitalization. The cutoff values for ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA and ESM\u003csub\u003eCT\u003c/sub\u003e predicting FOIS change\u0026thinsp;\u0026ge;\u0026thinsp;2 were calculated in the analyzed participants. Consequently, the cutoff value for ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA was 10.264 cm\u0026sup2;/m\u0026sup2;, and that for ESM\u003csub\u003eCT\u003c/sub\u003e was 36.020 HU (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Based on these cutoff values, the 452 participants were classified into four groups: High ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA・ESM\u003csub\u003eCT\u003c/sub\u003e, Low ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA, Low ESM\u003csub\u003eCT\u003c/sub\u003e, and Low ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA・ESM\u003csub\u003eCT\u003c/sub\u003e (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). There were 105 patients in the high ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA・ESM\u003csub\u003eCT\u003c/sub\u003e group, 87 in the low ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA group, 146 in the low ESM\u003csub\u003eCT\u003c/sub\u003e group, and 114 in the low ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA・ESM\u003csub\u003eCT\u003c/sub\u003e group. The percentage of patients with both muscle mass and muscle quality decline was 25.2%.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eComparison of patient characteristics in each group\u003c/h3\u003e\n\u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e shows the results of the comparison of patient characteristics in each group. In terms of age, the Low ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA group showed a tendency toward older age. The Low ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA・ESM\u003csub\u003eCT\u003c/sub\u003e group had a median age of 88.0 years, and the ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA・ESM\u003csub\u003eCT\u003c/sub\u003e group showed a similar tendency with a median age of 87.0 years among the four groups. Regarding A-DROP, which indicates severity, 26 patients (22.9%) in the Low ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA・ESM\u003csub\u003eCT\u003c/sub\u003e group were classified as severe or very severe, a proportion higher than that in the other groups. There were no significant differences between the four groups in terms of mechanical ventilation, intravenous antibiotic administration, WBC, and CRP. Regarding ADL performance, both the FIM at the start of pulmonary rehabilitation and the FIM at discharge were significantly lower in the Low ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA group and the Low ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA・ESM\u003csub\u003eCT\u003c/sub\u003e group. Regarding the rate of change in discharge location, the Low ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA group showed a significantly higher rate of 26.4% compared with the other groups. Furthermore, the length of hospital stay was significantly longer in the Low ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA group at 26.0 days.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eComparison of patient characteristics in each group\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"7\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eVariables\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eHigh ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA・ESM\u003csub\u003eCT\u003c/sub\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eLow ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eLow ESM\u003csub\u003eCT\u003c/sub\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eLow ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA・ESM\u003csub\u003eCT\u003c/sub\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003ep-value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;105)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;87)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;146)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;114)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eyears\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e84.00 [77.00, 89.00]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e88.00 [80.50, 92.00]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e81.50 [74.25, 87.00]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e87.00 [83.00, 91.00]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSex (male)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eno (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e65 (61.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e38 (43.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e94 (64.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e58 (50.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.007\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBMI\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ekg/m\u0026sup2;\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e20.90 [18.06, 24.14]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e20.36 [18.31, 23.61]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e20.10 [18.00, 22.67]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e20.42 [17.79, 22.72]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.472\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCCI\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003escore\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.00 [1.00, 3.00]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2.00 [1.00, 3.00]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2.00 [1.00, 2.75]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2.00 [1.00, 3.00]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.534\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eA-DROP\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003escore\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.00 [1.00, 2.00]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2.00 [1.00, 2.00]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2.00 [1.00, 2.00]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2.00 [1.00, 2.00]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.019\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003emild, no (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5 (4.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0 (0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e14 (9.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1 (0.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.012\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003emoderate, no (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e81 (77.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e69 (79.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e109 (74.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e87 (76.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003esevere, no (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e15 (14.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e15 (17.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e17 (11.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e24 (21.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003every severe, no (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4 (3.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3 (3.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e6 (4.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2 (1.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLTCI\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eindependent level, no (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e55 (52.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e24 (27.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e82 (56.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e38 (33.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003esupport level, no (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e28 (26.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e23 (26.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e36 (24.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e31 (27.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ecare level, no (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e22 (21.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e40 (46.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e28 (19.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e45 (39.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMechanical ventilation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eno (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3 (2.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1 (1.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1 (0.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1 (0.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.469\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIntravenous antibiotic administration\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003edays\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e9.00 [7.00, 12.00]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e10.00 [7.00, 12.00]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e8.50 [7.00, 13.00]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e9.00 [6.25, 13.75]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.563\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOral or EN within 48 hours\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eno (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e84 (80.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e68 (78.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e129 (88.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e84 (73.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.023\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePR within 48 hours\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eno (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e62 (59.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e53 (60.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e84 (57.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e64 (56.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.914\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eWBC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026times;10\u003csup\u003e2\u003c/sup\u003e/\u0026micro;L\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e103.00 [75.00, 128.00]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e101.00 [67.50, 129.50]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e95.50 [69.25, 137.50]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e103.50 [73.00, 129.75]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.855\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCRP\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003emg/dL\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8.99 [2.32, 14.37]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e6.14 [2.78, 13.20]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e7.60 [2.60, 13.42]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e7.05 [2.01, 13.27]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.692\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAlb\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eg/dL\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3.49 [3.10, 3.70]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.30 [2.95, 3.55]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3.26 [2.92, 3.62]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e3.26 [2.90, 3.59]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.014\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHb\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eg/dL\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e12.00 [11.10, 12.90]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e11.20 [10.05, 12.25]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e11.65 [10.53, 13.05]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e11.35 [10.22, 12.90]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.028\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFIM score at the start of PR\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003epoints\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e73.00 [45.00, 93.00]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e47.00 [30.50, 69.50]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e88.00 [60.25, 103.00]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e53.50 [32.00, 80.00]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFIM score at discharge\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003epoints\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e93.00 [59.00, 111.00]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e56.00 [37.00, 90.50]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e104.00 [81.00, 116.00]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e66.50 [36.00, 97.00]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eESM\u003csub\u003eCSA\u003c/sub\u003e/BSA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ecm\u003csup\u003e2\u003c/sup\u003e/m\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e13.03 [11.42, 15.10]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e7.60 [5.57, 8.86]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e13.07 [11.59, 14.98]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e7.81 [5.78, 9.23]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eESM\u003csub\u003eCT\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eHU\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e41.86 [39.29, 45.28]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e42.41 [40.31, 47.84]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e20.85 [10.96, 30.02]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e24.95 [11.52, 30.81]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eResidence location before hospitalization\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eHome, no (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e77 (73.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e41 (47.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e121 (82.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e64 (56.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eResidence location after hospital discharge\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eHome, no (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e68 (64.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e33 (37.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e111 (76.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e54 (47.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRate of change in discharge location\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eno (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e14 (13.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e23 (26.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e15 (10.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e18 (15.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.010\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLength of hospital stay\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003edays\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e19.00 [11.00, 33.00]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e26.00 [15.50, 43.50]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e17.00 [11.00, 33.75]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e21.00 [13.00, 38.00]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.041\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"7\" nameend=\"c7\" namest=\"c1\"\u003e \u003cp\u003eData are presented as Median (25th and 75th percentiles) or numbers.\u003c/p\u003e \u003cp\u003eStatistical analysis: Kruskal-Wallis test, χ\u0026sup2; test\u003c/p\u003e \u003cp\u003eAlb: albumin, BMI: body mass index, BSA: body surface area, CCI: Charlson comorbidity index, CRP: C-reactive protein, EN: enteral nutrition, ESM\u003csub\u003eCSA\u003c/sub\u003e: cross-sectional area of the erector spinae muscles, ESM\u003csub\u003eCT\u003c/sub\u003e: mean radiographic density of the erector spinae muscles, FIM: functional independence measure, Hb: hemoglobin, HU: Hounsfield unit, LTCI: long term care insurance, PR: pulmonary rehabilitation, WBC: white blood cell\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e\n\u003ch3\u003eComparison of FOIS before hospitalization and at discharge in each group\u003c/h3\u003e\n\u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e presents the comparison of FOIS scores before hospitalization and at discharge for each group. In the High ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA・ESM\u003csub\u003eCT\u003c/sub\u003e and Low ESM\u003csub\u003eCT\u003c/sub\u003e groups, FOIS decreased from Level 7 to Level 6, whereas in the Low ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA and Low ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA・ESM\u003csub\u003eCT\u003c/sub\u003e groups, FOIS decreased from Level 7 to Level 5, indicating a greater change. In addition, among patients who switched to tube feeding owing to difficulty with oral intake, the Low ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA group had the highest number of cases (9 cases, 10.3%) compared with the other groups.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eComparison of pre-admission and discharge FOIS in each group\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"7\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eVariables\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eHigh ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA・ESM\u003csub\u003eCT\u003c/sub\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eLow ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eLow ESM\u003csub\u003eCT\u003c/sub\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eLow ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA・ESM\u003csub\u003eCT\u003c/sub\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003ep-value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;105)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;87)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;146)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;114)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFOIS score before hospitalization\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003escore\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7.00 [7.00, 7.00]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e7.00 [6.00, 7.00]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e7.00 [7.00, 7.00]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e7.00 [6.00, 7.00]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.019\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLevel.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0 (0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0 (0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0 (0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0 (0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.189\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLevel.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0 (0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0 (0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0 (0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0 (0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLevel.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0 (0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1 (1.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0 (0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1 (0.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLevel.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2 (1.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e5 (5.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e7 (4.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e4 (3.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLevel.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10 (9.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e14 (16.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e10 (6.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e20 (17.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLevel.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e14 (13.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e12 (13.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e15 (10.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e15 (13.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLevel.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e79 (75.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e55 (63.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e114 (78.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e74 (64.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFOIS score at discharge\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003escore\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6.00 [5.00, 6.00]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e5.00 [4.00, 6.00]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e6.00 [5.00, 6.00]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e5.00 [5.00, 6.00]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLevel.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5 (4.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e9 (10.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4 (2.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e8 (7.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLevel.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0 (0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2 (2.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1 (0.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1 (0.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLevel.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0 (0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0 (0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0 (0.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1 (0.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLevel.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e13 (12.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e17 (19.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e10 (6.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e13 (11.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLevel.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e24 (22.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e32 (36.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e38 (26.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e42 (36.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLevel.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e44 (41.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e22 (25.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e62 (42.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e40 (35.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLevel.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e19 (18.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e5 (5.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e31 (21.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e9 (7.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"7\" nameend=\"c7\" namest=\"c1\"\u003e \u003cp\u003eData are presented as Median (25th and 75th percentiles) or numbers.\u003c/p\u003e \u003cp\u003eStatistical analysis: Kruskal\u0026ndash;Wallis test, χ\u0026sup2; test\u003c/p\u003e \u003cp\u003eBSA: body surface area, ESM\u003csub\u003eCSA\u003c/sub\u003e: cross-sectional area of the erector spinae muscles, ESM\u003csub\u003eCT\u003c/sub\u003e: mean radiographic density of the erector spinae muscles, FOIS: functional oral intake scale\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003eCorrelation between ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA and ESM\u003csub\u003eCT\u003c/sub\u003e and FOIS change\u003c/h2\u003e \u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e presents the results of multiple logistic regression analysis with FOIS change\u0026thinsp;\u0026ge;\u0026thinsp;2 as the objective variable. In univariate analysis, FOIS change and Low ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA were significantly associated (OR: 1.94, 95% CI: 1.07\u0026ndash;3.51, p\u0026thinsp;=\u0026thinsp;0.028). Low ESM\u003csub\u003eCT\u003c/sub\u003e and Low ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA・ESM\u003csub\u003eCT\u003c/sub\u003e showed no significant correlation. After adjusting for age, sex, BMI, CCI, A-DROP, mechanical ventilation, intravenous antibiotic administration, initiation of pulmonary rehabilitation within 48 hours, and initiation of oral intake or enteral nutrition within 48 hours, multivariate analysis revealed that Low ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA was significantly associated with FOIS change (OR: 1.97, 95% CI: 1.05\u0026ndash;3.69, p\u0026thinsp;=\u0026thinsp;0.035).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eRelationship between muscle mass and muscle quality of erector spinae muscles and FOIS changes\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eUnadjusted model\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e \u003cp\u003eAdjusted model\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eOR (95% CI)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003ep-value\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eOR (95% CI)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003ep-value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHigh ESM\u003csub\u003eCSA\u003c/sub\u003e/BSAཥESM\u003csub\u003eCT\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.00 (Reference)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.00 (Reference)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLow ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.94 (1.07\u0026ndash;3.51)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.028\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.97 (1.05\u0026ndash;3.69)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.035\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLow ESM\u003csub\u003eCT\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.64 (0.36\u0026ndash;1.13)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.126\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.71 (0.39\u0026ndash;1.28)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.253\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLow ESM\u003csub\u003eCSA\u003c/sub\u003e/BSAཥESM\u003csub\u003eCT\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.23 (0.70\u0026ndash;2.17)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.468\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.15 (0.63\u0026ndash;2.10)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.648\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"5\" nameend=\"c5\" namest=\"c1\"\u003e \u003cp\u003eStatistical analysis: multiple logistic regression analysis. OR: odds ratio, 95% CI: 95% confidence interval.\u003c/p\u003e \u003cp\u003eAdjusted models included age, sex, BMI, CCI, A-DROP, mechanical ventilation, intravenous antibiotic administration, PR within 48 hours, and oral or enteral nutrition within 48 hours.\u003c/p\u003e \u003cp\u003eCutoff value for ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA: 10.264 cm\u003csup\u003e2\u003c/sup\u003e/m\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e \u003cp\u003eCutoff value for ESM\u003csub\u003eCT\u003c/sub\u003e: 36.020 HU\u003c/p\u003e \u003cp\u003eBMI: body mass index, BSA: body surface area, CCI: Charlson comorbidity index, ESM\u003csub\u003eCSA\u003c/sub\u003e: cross-sectional area of the erector spinae muscles, ESM\u003csub\u003eCT\u003c/sub\u003e: mean radiographic density of the erector spinae muscles, FOIS: functional oral intake scale, PR: pulmonary rehabilitation\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eIn this study, we examined the relationship between swallowing dysfunction during hospitalization in older patients with pneumonia and muscle mass (ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA) and muscle quality (ESM\u003csub\u003eCT\u003c/sub\u003e) measured using chest CT images. The findings showed that changes in FOIS during hospitalization in older patients with pneumonia were significantly greater in cases of Low ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA, which reflects reduced muscle mass, and Low ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA・ESMCT, indicating a decrease in both muscle mass and muscle quality, with Low ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA having the strongest influence. Based on these findings, this study is the first to demonstrate a correlation between swallowing dysfunction during hospitalization and muscle mass measured by chest CT imaging in older patients with pneumonia. These findings support the importance of identifying factors that can predict swallowing dysfunction without additional testing by relying on chest CT images, which are often obtained in older patients with pneumonia.\u003c/p\u003e \u003cp\u003eRecently, attention has been focused on the relationship between sarcopenia and swallowing function. Previous studies [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e] have also shown that sarcopenia is independently associated with dysphagia. A position paper on sarcopenia and dysphagia published in 2019 also includes \u0026ldquo;systemic skeletal muscle loss\u0026rdquo; in its diagnostic algorithm, indicating that skeletal muscle loss is an important factor in dysphagia [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe ESMs examined in this study have several roles that are believed to contribute to physical function. First, the ESM is related to respiratory function. The ESM is one of the important respiratory accessory muscles, and previous studies have shown that ESM muscle mass measured using chest CT images is associated with respiratory function, such as forced expiratory volume in one second and vital capacity [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. Furthermore, respiratory function is significantly associated with cough strength, which is considered important in preventing pneumonia [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e], and individuals who developed aspiration pneumonia had significantly reduced cough strength [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]. There is also a close relationship between swallowing and respiratory function. A study of patients with chronic obstructive pulmonary disease reported a significant association between respiratory-swallowing dyssynchrony and respiratory function and the frequency of acute exacerbations [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. These findings suggest that reduced ESM muscle mass may affect swallowing function through its impact on declining respiratory function.\u003c/p\u003e \u003cp\u003eSecondly, the ESM is related to posture control. Swallowing and posture are closely related, and among the pathological background diseases leading to asymptomatic or overt aspiration, age-related skeletal changes, such as kyphosis and scoliosis, are also described [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. The ESM is one of the critical postural muscles, and a decrease in the cross-sectional area and density of the thoracic trunk muscles is significantly associated with thoracic kyphosis [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eFurthermore, trunk muscle mass has been reported to be significantly correlated with swallowing-related muscle mass [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]. Previous studies have reported a 31% prevalence of dysphagia among patients with sarcopenia [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]. Sarcopenia has been reported to be significantly associated with the development of dysphagia during hospitalization [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]. Therefore, decreased ESM muscle mass measured by CT in this study may be associated with a decline in swallowing function during hospitalization.\u003c/p\u003e \u003cp\u003eAlthough a decrease in trunk muscle mass does not directly affect swallowing function, it can indirectly create unfavorable conditions for swallowing, which may contribute to the onset of aspiration pneumonia.\u003c/p\u003e \u003cp\u003eHowever, in this study, ESM\u003csub\u003eCT\u003c/sub\u003e, an indicator of muscle quality, was not associated with swallowing dysfunction either alone or in combination, which differs from previous findings [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. This finding may be due to the conditions and characteristics of the skeletal muscles measured. The ESM is generally considered to have a higher distribution of Type I fibers than Type II fibers [\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e], which is thought to favor muscle endurance rather than muscle strength. In a study by Akazawa et al. [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e], the target muscle was the quadriceps femoris, which has a higher distribution of Type II fibers that favor muscle strength rather than muscle endurance, and this characteristic was considered to have a high correlation with the strength of the swallowing muscles. In a study by Jing et al. [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e], muscle mass was measured at the level of the 12th thoracic vertebra, as in this study, but the difference between their findings and ours was likely due to their measurement of muscles other than the ESMs. In the future, it will be necessary to examine the effects of muscle quality on swallowing dysfunction in older patients with pneumonia, including muscles other than the ESM.\u003c/p\u003e \u003cp\u003eBased on the above, evaluating muscle mass reduction in older patients with pneumonia using ESM may be an essential factor in predicting future swallowing dysfunction.\u003c/p\u003e \u003cp\u003eThis study has some limitations. First, this is a single-center study, and there are concerns regarding the applicability of the results to other facilities. Therefore, it will be necessary to explore its application in clinical settings through multi-facility collaborative research. Second, in this study, the relationship between muscle mass reduction and muscle quality deterioration in muscles involved in swallowing, which are thought to be directly related to swallowing function, remains unclear. In the future, it will be necessary to use ultrasound to measure the muscle mass and muscle quality of the muscles involved in swallowing and examine their correlation. Third, this study examined muscle mass and muscle quality at a single time point during hospitalization and did not assess skeletal muscle changes after hospitalization. Previous studies have shown that muscle mass measured by ESM on chest CT images decreases during treatment in older patients with aspiration pneumonia [\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e]. Further study is needed to determine whether such longitudinal changes in ESM muscle mass and muscle quality are associated with clinical outcomes. Fourth, this study focused on the ESM but did not examine other muscles. Therefore, it is necessary to examine other muscles as indicators to determine whether the results of this study apply to muscles beyond the ESM or whether they are specific to the ESM.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eThe results of this study suggest that muscle mass measurement using chest CT images is strongly associated with a decline in swallowing function during hospitalization in older patients with pneumonia. Therefore, evaluating skeletal muscles using chest CT images, which are commonly obtained during the treatment of pneumonia in older patients, is feasible in daily clinical practice and provides important information for predicting decline in swallowing function.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eAlb\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;albumin\u003c/p\u003e\n\u003cp\u003eBMI\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;body mass index\u003c/p\u003e\n\u003cp\u003eBSA\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;body surface area\u003c/p\u003e\n\u003cp\u003eCCI\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Charlson comorbidity index\u003c/p\u003e\n\u003cp\u003eCI\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;confidence interval\u003c/p\u003e\n\u003cp\u003eCRP\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;c-reactive protein\u003c/p\u003e\n\u003cp\u003eCT\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;computed tomography\u003c/p\u003e\n\u003cp\u003eEN\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;enteral nutrition\u003c/p\u003e\n\u003cp\u003eESM\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;erector spinae muscles\u003c/p\u003e\n\u003cp\u003eESM\u003csub\u003eCSA\u003c/sub\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;cross-sectional area of the erector spinae muscles\u003c/p\u003e\n\u003cp\u003eESM\u003csub\u003eCT\u003c/sub\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;mean radiographic density of the erector spinae muscles\u003c/p\u003e\n\u003cp\u003eFIM\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;functional independence measure\u003c/p\u003e\n\u003cp\u003eFOIS\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;functional oral intake scale\u003c/p\u003e\n\u003cp\u003eHb\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;hemoglobin\u003c/p\u003e\n\u003cp\u003eHU\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;hounsfield unit\u003c/p\u003e\n\u003cp\u003eLTCI\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;long term care insurance\u003c/p\u003e\n\u003cp\u003eOR\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;odds ratio\u003c/p\u003e\n\u003cp\u003ePR\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;pulmonary rehabilitation\u003c/p\u003e\n\u003cp\u003eROC\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;receiver operating characteristic\u003c/p\u003e\n\u003cp\u003eWBC\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;white blood cell\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgment\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe thank the Department of Internal Medicine and the Department of Rehabilitation Technology at Sanuki Municipal Hospital for their cooperation in data collection. We would like to thank Editage (www.editage.jp) for English language editing.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eY\u003c/strong\u003e\u003cstrong\u003euichi\u003c/strong\u003e\u003cstrong\u003eMurakawa\u003c/strong\u003e: Writing \u0026ndash; original draft, Validation, Resources, Methodology, Investigation, Formal analysis, Data curation, Conceptualization. \u003cstrong\u003eA\u003c/strong\u003e\u003cstrong\u003ekira\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eT\u003c/strong\u003e\u003cstrong\u003eamaki\u003c/strong\u003e: Writing \u0026ndash; review \u0026amp; editing, Supervision, Project administration, Methodology, Investigation, Formal analysis, Conceptualization. \u003cstrong\u003eR\u003c/strong\u003e\u003cstrong\u003eyota\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eM\u003c/strong\u003e\u003cstrong\u003eatsuzawa\u003c/strong\u003e: Writing \u0026ndash; review \u0026amp; editing, Methodology, Investigation, Formal analysis. \u003cstrong\u003eS\u003c/strong\u003e\u003cstrong\u003ehinjiro\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eM\u003c/strong\u003e\u003cstrong\u003eiyazaki\u003c/strong\u003e: Writing \u0026ndash; review \u0026amp; editing, Methodology, Investigation. \u003cstrong\u003eK\u003c/strong\u003e\u003cstrong\u003eoji\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eF\u003c/strong\u003e\u003cstrong\u003eujishima\u003c/strong\u003e: Methodology, Formal analysis, Data curation. \u003cstrong\u003eT\u003c/strong\u003e\u003cstrong\u003eatsuma\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eH\u003c/strong\u003e\u003cstrong\u003eori\u003c/strong\u003e: Methodology, Formal analysis, Data curation. \u003cstrong\u003eM\u003c/strong\u003e\u003cstrong\u003eiki\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eN\u003c/strong\u003e\u003cstrong\u003eaide\u003c/strong\u003e: Methodology, Formal analysis, Data curation. \u003cstrong\u003eK\u003c/strong\u003e\u003cstrong\u003eenichiro\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eS\u003c/strong\u003e\u003cstrong\u003eakai\u003c/strong\u003e: Writing \u0026ndash; review \u0026amp; editing, Methodology, Investigation, Formal analysis, Data curation. \u003cstrong\u003eT\u003c/strong\u003e\u003cstrong\u003eomoya\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eI\u003c/strong\u003e\u003cstrong\u003eshii\u003c/strong\u003e: Writing \u0026ndash; review \u0026amp; editing, Methodology, Investigation, Formal analysis, Data curation.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors did not receive support from any organization for the submitted work.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability statement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe data collected/analyzed by the current study have not been released to the public for privacy reasons. If there is a reasonable request, we will consider submitting the data.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAlthough participants in this study did not provide written or verbal informed consent, they were allowed to refuse or withdraw from participation at any time. The opt-out procedure conforms to the Japanese Ethical Guidelines for Epidemiological Research for observational studies that use existing data. The study protocol, including the consent procedure (informed consent waiver), was approved by the Ethics Review Board of Hyogo Medical University (approval number: 5058) and conducted in accordance with the principles of the Declaration of Helsinki.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interest\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThere is no conflict of interest.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eClinical trial number\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor details\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003csup\u003e1\u003c/sup\u003e Graduate School of Rehabilitation Science, Hyogo Medical University, 1-3-6 Minatojima, Chuo Ward, Kobe, Hyogo 650-8530 Japan\u003c/p\u003e\n\u003cp\u003e\u003csup\u003e2\u003c/sup\u003e Department of Rehabilitation Technology, Sanuki Municipal Hospital, 387-1 Ishida Higashi Kou, Sangawa-cho, Sanuki City, Kagawa 769-2393 Japan\u003c/p\u003e\n\u003cp\u003e\u003csup\u003e3\u003c/sup\u003e Rehabilitation Center, KKR Takamatsu Hospital, 4-18 Tenjinmae, Takamatsu City, Kagawa 760-0018, Japan\u003c/p\u003e\n\u003cp\u003e\u003csup\u003e4\u003c/sup\u003e Department of Respiratory Medicine, Sanuki Municipal Hospital, 387-1 Ishida Higashi Kou, Sangawa-cho, Sanuki City, Kagawa 769-2393 Japan\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003eMorimoto K, Suzuki M, Ishifuji T, et al. 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A new method of classifying prognostic comorbidity in longitudinal studies: development and validation. J Chronic Dis. 1987;40(5):373-83. https://doi.org/10.1016/0021-9681(87)90171-8.\u003c/li\u003e\n \u003cli\u003eShindo Y, Sato S, Maruyama E, et al. Comparison of severity scoring systems A-DROP and CURB-65 for community-acquired pneumonia. Respirology. 2008;13(5):731-5. https://doi.org/10.1111/j.1440-1843.2008.01329.x.\u003c/li\u003e\n \u003cli\u003eMinegishi Y, Inoue S, Sato K, et al. Smaller erector spinae muscle size is associated with inability to recover activities of daily living after pneumonia treatment. Respir Investig. 2019;57(2):191-197. https://doi.org/10.1016/j.resinv.2018.11.002.\u003c/li\u003e\n \u003cli\u003eOshima Y, Sato S, Chen-Yoshikawa T.F, et al. Quantity and quality of antigravity muscles in patients undergoing living-donor lobar lung transplantation: 1-year longitudinal analysis using chest computed tomography images. ERJ Open Res. 2020;6(2):00205-2019. https://doi.org/10.1183/23120541.00205-2019.\u003c/li\u003e\n \u003cli\u003eCrary M.A, Mann G.D, Groher M.E. Initial psychometric assessment of a functional oral intake scale for dysphagia in stroke patients. Arch Phys Med Rehabil. 2005;86(8):1516-20. https://doi.org/10.1016/j.apmr.2004.11.049.\u003c/li\u003e\n \u003cli\u003eKanda Y. Investigation of the freely available easy-to-use software \u0026apos;EZR\u0026apos; for medical statistics. Bone Marrow Transplant. 2013;48(3):452-8. https://doi.org/10.1038/bmt.2012.244.\u003c/li\u003e\n \u003cli\u003eCha S, Kim W.S, Kim K.W, et al. Sarcopenia is an Independent Risk Factor for Dysphagia in Community-Dwelling Older Adults. Dysphagia. 2019;34(5):692-697. https://doi.org/10.1007/s00455-018-09973-6.\u003c/li\u003e\n \u003cli\u003eFujishima I, Fujiu-Kurachi M, Arai H, et al. Sarcopenia and dysphagia: Position paper by four professional organizations. Geriatr Gerontol Int. 2019;19(2):91-97. https://doi.org/10.1111/ggi.13591.\u003c/li\u003e\n \u003cli\u003eGauld L.M, Boynton A. Relationship between peak cough flow and spirometry in Duchenne muscular dystrophy. Pediatr Pulmonol. 2005;39(5):457-60. https://doi.org/10.1002/ppul.20151.\u003c/li\u003e\n \u003cli\u003eSohn D, Park G.Y, Koo H, et al. Determining Peak Cough Flow Cutoff Values to Predict Aspiration Pneumonia Among Patients With Dysphagia Using the Citric Acid Reflexive Cough Test. Arch Phys Med Rehabil. 2018;99(12):2532-2539.e1. https://doi.org/10.1016/j.apmr.2018.06.015.\u003c/li\u003e\n \u003cli\u003eNagami S, Oku Y, Yagi N, et al. Breathing-swallowing discoordination is associated with frequent exacerbations of COPD. BMJ Open Respir Res. 2017;4(1):000202. https://doi.org/10.1136/bmjresp-2017-000202.\u003c/li\u003e\n \u003cli\u003eTeramoto S. The current definition, epidemiology, animal models and a novel therapeutic strategy for aspiration pneumonia. Respir Investig. 2022;60(1):45-55. https://doi.org/10.1016/j.resinv.2021.09.012.\u003c/li\u003e\n \u003cli\u003eLorbergs A.L, Allaire B.T, Yang L, et al. A Longitudinal Study of Trunk Muscle Properties and Severity of Thoracic Kyphosis in Women and Men: The Framingham Study. J Gerontol A Biol Sci Med Sci. 2019;74(3):420-427. https://doi.org/10.1093/gerona/gly056.\u003c/li\u003e\n \u003cli\u003eYamaguchi K, Nakagawa K, Yoshimi K, et al. Association between characteristics of swallowing-related muscles and trunk muscle mass. Sci Rep. 2023;13(1):7814. https://doi.org/10.1038/s41598-023-34905-2.\u003c/li\u003e\n \u003cli\u003eLi Y, Li J, Xian L, et al. Prevalence and Risk Factors of Dysphagia in Patients with Sarcopenia: A Meta-Analysis. Dysphagia. 2026;41(1):218-228. https://doi.org/10.1007/s00455-025-10872-w.\u003c/li\u003e\n \u003cli\u003eYoshimura Y, Wakabayashi H, Bise T, et al. Sarcopenia is associated with worse recovery of physical function and dysphagia and a lower rate of home discharge in Japanese hospitalized adults undergoing convalescent rehabilitation. Nutrition. 2019;61:111-118. https://doi.org/10.1016/j.nut.2018.11.005.\u003c/li\u003e\n \u003cli\u003eJohnson M.A, Polgar J, Weightman D, et al. (1973) Data on the distribution of fibre types in thirty-six human muscles. An autopsy study. J Neurol Sci. 1973;18(1):111-29. https://doi.org/10.1016/0022-510x(73)90023-3.\u003c/li\u003e\n \u003cli\u003eKomatsu R, Okazaki T, Ebihara S, et al. Aspiration pneumonia induces muscle atrophy in the respiratory, skeletal, and swallowing systems. J Cachexia Sarcopenia Muscle. 2018;9(4):643-653. https://doi.org/10.1002/jcsm.12297.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"pneumonia, erector spinae muscle, muscle mass, muscle quality, swallowing function","lastPublishedDoi":"10.21203/rs.3.rs-9201548/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9201548/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground:\u003c/strong\u003e Trunk muscle mass and quality may be related to swallowing function; however, it is unclear whether the same trend is observed in older patients with pneumonia. We aimed to determine the impact of the mass and quality of the erector spinae muscles (ESM), measured by chest computed tomography (CT), on the decline in swallowing function during hospitalization in older patients with pneumonia.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods:\u003c/strong\u003e The participants were patients hospitalized at Sanuki Municipal Hospital with a diagnosis of pneumonia who underwent pulmonary rehabilitation. The cross-sectional area of the ESM (ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA) was measured using chest CT images as an indicator of muscle mass, and the CT value of the ESM (ESM\u003csub\u003eCT\u003c/sub\u003e) was measured as an indicator of muscle quality. After calculating the cutoff values of ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA and ESM\u003csub\u003eCT\u003c/sub\u003e that predict a score of ≥2 on the Functional Oral Intake Scale (FOIS), we classified the participants (n=452) into four groups: High ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA・ESM\u003csub\u003eCT\u003c/sub\u003e, Low ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA, Low ESM\u003csub\u003eCT\u003c/sub\u003e, and Low ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA・ESM\u003csub\u003eCT\u003c/sub\u003e.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults:\u003c/strong\u003e Multiple logistic regression analysis, adjusted for confounders, showed that Low ESM\u003csub\u003eCSA\u003c/sub\u003e/BSA was significantly associated with FOIS change during hospitalization.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusions:\u003c/strong\u003e Our results suggest that muscle mass is strongly associated with a decline in swallowing function during hospitalization in older patients with pneumonia.\u003c/p\u003e","manuscriptTitle":"Impact of erector spinae muscle mass and quality on decline in swallowing function during hospitalization in older patients with pneumonia: single-center retrospective observational study in Japan","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-10 16:50:08","doi":"10.21203/rs.3.rs-9201548/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"d9f3ccb1-f042-49bc-9ba4-b5e8ed7c7f1d","owner":[],"postedDate":"April 10th, 2026","published":true,"recentEditorialEvents":[{"type":"decision","content":"Rejected","date":"2026-05-08T17:15:31+00:00","index":"","fulltext":""}],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-05-08T17:25:20+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-10 16:50:08","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9201548","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9201548","identity":"rs-9201548","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}