Outpatient surgery and unplanned overnight admission in bilateral inguinal hernia repair: a population-based study

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Magdalena Llompart-Coll, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-3576250/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 6 You are reading this latest preprint version Abstract Purpose The use of outpatient surgery in inguinal hernia is heterogeneous despite clinical recommendations. This study aimed to analyze the utilization trend of outpatient surgery for bilateral inguinal hernia repair (BHIR) in Spain and identify the factors associated with outpatient surgery choice and unplanned overnight admission. Methods A retrospective observational study of patients undergoing BIHR from 2016 to 2021 was conducted. The clinical-administrative database of the Spanish Ministry of Health RAE-CMBD was used. Patient characteristics undergoing outpatient and inpatient surgery were compared. A multivariable logistic regression analysis was performed to identify factors associated with outpatient surgery choice and unplanned overnight admission. Results A total of 30,940 RHIBs were performed; 63% were inpatient surgery, and 37% were outpatient surgery. The rate of outpatient surgery increased from 30% in 2016 to 41% in 2021 (p < 0.001). Higher rates of outpatient surgery were observed across hospitals with a higher number of cases per year (p < 0.001). Factors associated with outpatient surgery choice were: age under 65 years (OR: 2.01, 95% CI: 1.92–2.11), hospital volume (OR: 1.59, 95% CI: 1.47–1.72), primary hernia (OR: 1.89, 95% CI: 1.71–2.08), and laparoscopic surgery (OR: 1.47, 95% CI: 1.39–1.56). Comorbidities were negatively associated with outpatient surgery. Open surgery was associated (OR: 1.26, 95% CI: 1.09–1.47) with unplanned overnight admission. Conclusions Outpatient surgery for BHIR has increased in recent years but is still low. Older age and comorbidities were associated with lower rates of outpatient surgery. However, the laparoscopic repair was associated with increased outpatient surgery and lower unplanned overnight admission. bilateral inguinal hernia outpatient surgery unplanned overnight admission laparoscopic surgery Figures Figure 1 Figure 2 Figure 3 INTRODUCTION Inguinal hernia is a common surgical issue accounting for 75% of all abdominal wall hernias [ 1 ] and Inguinal hernia repair ranks among the most frequently conducted surgical interventions worldwide [ 2 , 3 ]. As such, changes in the type of hospitalization, utilization of minimally invasive surgical techniques, and rate of postoperative complications of inguinal hernia surgery can significantly impact the healthcare system. Advances in surgical and anesthetic techniques have increased the proportion of inguinal hernia repairs conducted as outpatient surgery [ 4 ]. Outpatient surgery offers several advantages, including early mobilization, increased patient satisfaction, decreased susceptibility to nosocomial infections and venous thromboembolism, and minimized costs associated with conventional inpatient care [ 5 – 8 ]. Nevertheless, the outpatient inguinal hernia repair rate remains variable despite its wide acceptance and international clinical guideline recommendation [ 3 , 9 ]. Patient characteristics, surgeon preferences, and health system incentives influence its choice. It is recommended that over 70% of adult inguinal hernia repairs should be conducted as outpatient surgery [ 10 – 12 ]. Some authors suggest that bilateral inguinal hernias should preferably receive hospital treatment due to the increased risk of perioperative complications [ 13 , 14 ]. In addition, bilateral inguinal hernia has been described as a predictor of ambulatory failure [ 14 ]. However, according to other studies, bilateral inguinal hernia is not a limitation for outpatient surgery and is not associated with an increased risk of failure [ 15 – 17 ]. Limited research exists on outpatient surgery utilization for inguinal hernia, and no specific studies exist on bilateral inguinal hernia. This study aimed to analyze the utilization trend of outpatient surgery for BHIR in Spain, identify the factors associated with the choice of outpatient surgery, and the factors associated with unplanned overnight admission in patients initially scheduled for outpatient surgery. MATERIALS AND METHODS Study design A retrospective observational study was conducted using the Hospital Discharge Registry of the Spanish Ministry of Health (Registro de Actividad de Atención Especializada-Conjunto Mínimo Básico de Datos, RAE-CMBD) [ 18 ]. In Spain, the RAE-CMBD is a mandatory registry of the diagnoses and healthcare procedures performed in all public and private hospitals nationwide, using the International Classification of Diseases Version 10 (ICD-10) codes. The data is obtained from the information in each patient's discharge report. It records three types of variables: patient identification, identification of the care episode, and clinical variables. The physician completes the hospital discharge information in the discharge report, and subsequently, the health coding specialist performs the coding of the information contained in the hospital discharge report. Study population Our study included patients who underwent BIHR in the Spanish National Health System hospitals from 2016 to 2021. The flowchart (Fig. 1 ) shows the ICD-10 diagnostic codes used to identify patients. Inclusion criteria: 1) Patients with main BIHR procedure and 2) Age greater than or equal to 15 years. Exclusion criteria: 1) Manual reduction of the hernia and 2) Emergency or unscheduled care. Variables analyzed Demographic characteristics and comorbidities Data analysis included age, sex, and comorbidities. The specific comorbidities were identified using ICD-10 diagnostic codes described by Quan et al. [ 19 ]. The specific comorbidities considered included arterial hypertension, heart disease, chronic lung disease, renal disease, liver disease, diabetes mellitus, obesity, peripheral vascular disease, cerebrovascular disease, rheumatic disease, and alcohol and tobacco abuse. Charlson and Elixhauser comorbidity indices were calculated for each patient. Supplementary material presents the ICD-10 codes used for comorbidities. Hospital volume The study analyzed the relation between the outpatient surgery rate and hospital volume, which was defined as the number of BIHRs performed by year. Characteristics of the hernia and surgery The pre-surgical presence of recurrent hernia and complicated hernia was recorded. The complicated hernia was defined as obstruction or gangrene in the diagnostic code. The surgical approach, open or laparoscopic, was recorded. Outpatient surgery Patients scheduled for inpatient and outpatient surgery for BIHR were identified. We used the variable "type of contact" from the RAE-CMBD database to identify patients initially scheduled for outpatient surgery. A comparative analysis between the two groups was conducted, and a multivariable analysis was performed to determine the factors associated with the choice of outpatient surgery. Unplanned overnight admission The unplanned overnight admission and unplanned readmission rate to the hospital are quality markers for ambulatory surgery units. Patients who required unplanned overnight admission among those initially scheduled for outpatient surgery were identified. Unplanned overnight admission was defined as a hospital stay lasting ≥ 1 day. Statistical analysis The Chi-square test was used for the qualitative variables. For quantitative variables with normal distribution, Student's t-test was used to compare between two groups. For non-normal distributions, the non-parametric Mann-Whitney U test was used. The Cochran-Armitage test was used for trend analysis of ordinal categorical variables, A multivariable logistic regression analysis was performed to identify factors associated with the choice of outpatient surgery and to identify factors associated with unplanned overnight admission. Statistical significance was set at p < 0.05. IBM SPSS 27.0 software (Armonk, NY: IBM Corp) was used for statistical analysis. Ethical aspects The analyzed data is anonymous and sourced from a database under the management of the Spanish Ministry of Health, adhering to the data protection regulations in Spain. Identifying patients at the individual or reporting unit level is impossible, and using information from clinical-administrative bases does not require the approval of a Medical Research Ethics Committee. RESULTS Utilization trend of outpatient surgery in BIHR Our study included 30,940 BIHR, 19,452 (63%) as inpatient surgeries, and 11,488 (37%) as outpatient surgeries. Over the analyzed period, there was a statistically significant upward trend in the utilization of outpatient surgery in the test of Cochran-Armitage (p < 0.001), increasing from 30% in 2016 to 41% in 2021 (Fig. 2 ). Hospital volume The outpatient surgery utilization rate was proportionally higher (p < 0.001) in hospitals with the highest number of BIHRs performed per year (Fig. 3 ). Demographic characteristics and comorbidity The mean age was higher in the inpatient surgery group than in the outpatient surgery group (63.58 ± 13.29 vs. 58.22 ± 12.99, p < 0.001), and there were no significant differences in sex between the two groups (Table 1 ). The comorbidities were higher in inpatient surgery group with a significant difference (p < 0.001). Table 1 Characteristics of the patients with bilateral inguinal hernia repair (2016–2021) Total N = 30,940 Inpatient N = 19,452 Outpatient N = 11,488 p-value Age, Mean ± SD 61.59 ± 13.43 63.58 ± 13.29 58.22 ± 12.99 < 0.001 Age < 65 years, N (%) 17,285 (55.9) 9,652 (49.6) 7,633 (66.4) < 0.001 Age ≥ 65 years, N (%) 13,655 (44.1) 9,800 (50,4) 3,855 (33.6) < 0.001 Sex, N (%) 0.942 Male 28,682 (92.7) 18,034 (92.7) 10,648 (92.7) Female 2,258 (7.3) 1,418 (7.3) 840 (7.3) Comorbidities, N (%) Arterial hypertension 8,030 (26) 6,594 (33.9) 1,436 (12.5) < 0.001 Heart disease 2,448 (7.9) 2,203 (11.3) 245 (2.1) < 0.001 Chronic pulmonary disease 1,874 (6.1) 1,543 (7.9) 331 (2.9) < 0.001 Renal disease 559 (1.8) 496 (2.5) 63 (0.5) < 0.001 Liver disease 517 (1.7) 410 (2.1) 107 (0.9) < 0.001 Diabetes mellitus 2,606 (8.4) 2,137 (11) 469 (4.1) < 0.001 Obesity 857 (2.8) 649 (3.3) 208 (1.8) < 0.001 Peripheral vascular disease 387 (1.3) 355 (1.8) 32 (0.3) < 0.001 Cerebrovascular disease 162 (0.5) 142 (0.7) 20 (0.2) < 0.001 Rheumatic disease 240 (0.8) 198 (1) 42 (0.4) < 0.001 Alcohol abuse 640 (2.1) 491 (2.5) 149 (1.3) < 0.001 Tobacco use 3,883 (12.6) 2893 (14.9) 990 (8.6) < 0.001 Charlson Index, Mean (SD) 0.3 ± 0.76 0.4 ± 0.89 0.12 ± 0.47 < 0.001 Elixhauser Index, Mean (SD) 0.76 ± 2.75 1.07 ± 3.17 0.23 ± 1.71 < 0.001 Hernia characteristics, N (%) Recurrent hernia 2,271 (7.3) 1,712 (8.8) 559 (4.9) < 0.001 Primary hernia 28,669 (92.7) 17,740 (91.2) 10,929 (95.1) < 0.001 Surgery approach, N (%) < 0.001 Open surgery 24,524 (79.3) 15,887 (81.7) 8,637 (75.2) Laparoscopy surgery 6,416 (20.7) 3,565 (18.3) 2,851 (24.8) Hospital volume, N (%) < 0.001 1–20 cases/year 10,795 (34.9) 7,205 (37) 3,590 (31.3) 20–40 cases/year 12,907 (41.7) 8,170 (42) 4,737 (41.2) 40–60 cases/year 4,462 (14.4) 2,617 (13.5) 1,845 (16.1) 60–80 cases/year 863 (2.8) 560 (2.9) 303 (2.6) >80 cases/year 1,913 (6.2) 900 (4.6) 1,013 (8.8) SD: standard deviation Characteristics of the hernia and surgery The proportion of recurrent hernia was higher in the inpatient surgery group (p < 0.001). The use of laparoscopic surgery was higher in the outpatient surgery group than in the inpatient surgery group (24.8% vs 18.3%, p < 0.001). Factors associated with the use of outpatient surgery In the multivariable logistic regression analysis, the factors independently associated with the choice of outpatient surgery were: age under 65 years (OR: 2.01, 95% CI: 1.92–2.11), hospital volume > 60 cases/year (OR: 1.59, 95% CI: 1.47–1.72), primary inguinal hernia (OR: 1.89, 95% CI: 1.71–2.08), and laparoscopic surgery (OR: 1.47, 95% CI: 1.39–1.56). The comorbidities presented a negative association with the choice of outpatient surgery (Table 2 ). Table 2 Univariable and multivariable analysis of factors associated with the choice of outpatient bilateral inguinal hernia repair. Univariable analysis Multivariable analysis OR (95% CI) p-value OR (95% CI) p-value Age < 65 years 2.01 (1.92–2.11) < 0.001 1.34 (1.27–1.41) 60 cases/year 1.59 (1.47–1.72) < 0.001 1.59 (1.46–1.72) < 0.001 Primary hernia 1.89 (1.71–2.08) < 0.001 1.78 (1,61-1.97) < 0.001 Arterial hypertension 0.28 (0.27–0.29) < 0.001 0.41 (0.38–0.44) < 0.001 Heart disease 0.17 (0.15–0.19) < 0.001 0.31 (0.29–0.36) < 0.001 Chronic pulmonary disease 0.34 (0.31–0.39) < 0.001 0.51 (0.45–0.58) < 0.001 Renal disease 0.21 (0.16–0.27) < 0.001 0.59 (0.45–0.78) 0.001 Liver disease 0.44 (0.35–0.54) < 0.001 0.59 (0.47–0.73) < 0.001 Diabetes mellitus 0.35 (0.31–0.38) < 0.001 0.64 (0.58–0.72) < 0.001 Obesity 0.53 (0.46–0.63) < 0.001 0.79 (0.67–0.93) 0.005 Peripheral vascular disease 0.15 (0.11–0.22) < 0.001 0.35 (0.24–0.51) < 0.001 Cerebrovascular disease 0.24 (0.15–0.38) < 0.001 0.37 (0.32–0.86) 0.01 Rheumatic disease 0.53 (0.26–0.49) < 0.001 0.53 (0.37–0.75) < 0.001 Laparoscopic surgery 1.47 (1.39–1.56) < 0.001 1.31 (1.24–1.39) < 0.001 OR: odds ratio, CI: confidence interval. Unplanned overnight admission Among the 11,488 patients initially scheduled for outpatient surgery, 1143 (9.9%) required an unplanned overnight admission. In this study, open surgery was independently associated (OR: 1.26, 95% CI: 1.09–1.47) with unplanned overnight admission, while hospital volume > 60 cases/year was negatively associated (OR: 0.16, 95% CI: 0.11–0.24) with unplanned overnight admission (Table 3 ). Table 3 Univariable and multivariable analysis of factors associated with unplanned overnight admissions of outpatient bilateral inguinal hernia repair. Univariable analysis Multivariable analysis OR (95% CI) p-value OR (95% CI) p-value Age ≥ 65 years 0.91 (0.79–1.03) 0.137 Sex Male 0.92 (0.72–1.17) 0.504 Hospital volume > 60 cases/year 0.16 (0.11–0.24) < 0.001 0.17 (0.11–0.24) < 0.001 Recurrent hernia 1.2 (0.92–1.57) 0.175 Arterial hypertension 1.49 (0.94–2.38) 0.091 Heart disease 1.27 (0.86–1.87) 0.226 Chronic pulmonary disease 0.89 (0.62–1.32) 0.585 Renal disease 0.15 (0.02–1.05) 0.056 Liver disease 0.93 (0.49–1.79) 0.834 Diabetes mellitus 0.79 (0.56–1.11) 0.173 Obesity 0.75 (0.45–1.26) 0.274 Peripheral vascular disease 0.29 (0.04–2.14) 0.225 Cerebrovascular disease 0.48 (0.07–3.56) 0.469 Rheumatic disease 0.95 (0.34–2.67) 0.926 Open surgery 1.26 (1.09–1.47) 0.002 1.23 (1.06–1.43) 0.007 OR: odds ratio, CI: confidence interval. DISCUSSION The use of outpatient surgery for BIHR has increased in recent years. Factors such as age below 65 years, larger hospital volume, primary inguinal hernia, and laparoscopic approach were associated with the choice of outpatient surgery. Conversely, comorbidities showed a negative association. Furthermore, open surgery was independently linked to unplanned overnight admission. The advantages of outpatient inguinal hernia surgery are widely recognized, including higher patient satisfaction rates and reduced costs [ 7 , 20 ]. Hospital-admitted inguinal hernia surgery costs 56% more than outpatient surgery [ 6 , 21 ]. Additionally, it enables better utilization of hospital resources by ensuring beds are available for patients with more severe conditions. The utilization of outpatient surgery for inguinal hernia repair has increased globally [ 22 , 23 ]. However, the proportion of use varies significantly across countries. Some countries have achieved high utilization rates exceeding 70%. Rates of 70% were reported in Denmark [ 24 ] and 74% in France [ 14 ]. In a study conducted in hospitals in northeast Italy, the rate was even higher at 76% [ 4 ]. While in other countries, such as Germany, the proportion of outpatient surgery in inguinal hernia repair was only 14% in 2019 [ 13 ]. A recent study in Spain reported that 54% of all inguinal hernia repairs were performed as outpatient procedures [ 25 ]. The variability in outpatient surgery utilization can be attributed to differences in patient selection criteria and economic incentives for hospitals and surgeons to promote outpatient surgeries [ 13 ]. The number of procedures performed by outpatient surgery in Spain could be greater through the application of measures by the National Health System that encourage hospitals to increase the use of outpatient surgery to optimize public health resources. In our analysis of bilateral hernias, we observed an increasing trend in outpatient surgery, from 30% in 2016 to 41% in 2021. In 2020, we observed an increase in the use of outpatient surgery up to 43%, probably influenced by the COVID-19 pandemic. However, the use of outpatient surgery in 2021 was 41%. Future studies are necessary to analyze whether the trend toward increased use of outpatient surgery observed during the year of the COVID-19 pandemic will continue in the coming years. The patient's age has been considered by some authors as a criterion for selecting candidates for outpatient surgery in inguinal hernia repair [ 26 , 27 ]. Our study found that age under 65 was independently associated with the choice of outpatient surgery. However, other studies have shown that older patients do not have higher complication rates than younger patients [ 8 , 28 , 29 ], suggesting that age should not be a contraindication for outpatient surgery [ 30 , 31 ]. Including elderly patients in outpatient surgery can increase utilization rates and provide them with the benefits of a shorter hospital stay, such as reduced cognitive impairment [ 32 ]. Our study found that comorbidities were negatively associated with the choice of outpatient surgery for BIHR. The Spanish Ministry of Health uses the classification of the American Society of Anesthesiologists (ASA) [ 33 ] in its recommendations for selecting candidate patients for outpatient surgery. It considers suitable patients with ASA 1, ASA 2, and ASA 3 without decompensation. However, studies conducted in inguinal hernia surgery suggest that comorbidities or the ASA score should not be a contraindication for outpatient surgery [ 34 , 35 ]. Utilizing outpatient surgery in patients with comorbidities could offer them the advantages of reduced risk for nosocomial infections and venous thromboembolic complications, to which they are more vulnerable [ 5 , 7 , 8 ]. The characteristics of the hernia can play a role in determining the suitability of outpatient surgery. Strangulated hernia and large inguinoscrotal hernia have been considered exclusion criteria in some studies [ 36 ]. However, some authors argue that recurrent hernia should not be a contraindication for outpatient surgery [ 14 , 17 ]. In our study, we found that recurrent hernia was negatively associated with the choice of outpatient surgery. Hospitals with higher case volumes and experienced surgeons tend to have shorter surgical times and lower complication rates [ 37 ]. These favorable outcomes are conducive to the implementation of outpatient surgery. In our study, we found that hospitals with a higher number of cases performed annually were more likely to choose outpatient surgery. Decreased postoperative pain is one of the main factors that favor outpatient surgery [ 38 ], and it is known that laparoscopic inguinal hernia repair is associated with reduced postoperative pain, faster recovery, and fewer complications [ 39 – 42 ]. However, the utilization rates are variable: 61% in Denmark [ 43 ], 38% in the USA [ 44 ], 23% in England [ 45 ] and 5.7% in Spain [ 46 ]. The high rate of use of laparoscopy in countries such as Denmark, where it reaches up to 96% in bilateral hernias [ 47 ], could be related to the high rates of use of outpatient surgery. The benefits of laparoscopic are greater in a bilateral inguinal hernia, and international clinical guidelines recommend performing BIHR using a laparoscopic approach [ 3 , 48 – 51 ]. Our study observed that laparoscopic repair was independently associated with the choice of outpatient surgery. However, despite these advantages, the utilization rate of laparoscopic bilateral inguinal hernia repair in Spain remains low, with a reported rate of 23% in 2019 [ 52 ]. Efforts to increase the laparoscopic BIHR rate could increase outpatient surgery utilization in these patients. Furthermore, although the higher cost of laparoscopic surgery is a limiting factor [ 53 ], the cost-effectiveness of outpatient surgery would offset this expense. The rate of unplanned admissions in ambulatory inguinal hernia surgery varies considerably in the literature, ranging from 0–19% [ 14 , 15 , 30 , 54 – 57 ]. In our study, we observed an unplanned overnight admission rate of 9.9%. Several published studies have been performed to identify predictors of unplanned admission to improve the outcomes of outpatient surgery for inguinal hernia. Some have identified ASA grades 3 and 4 as predictors of unplanned admission [ 14 , 54 , 56 ]. Other studies found that older patients, body mass index greater than 30, spinal anesthesia, and longer duration of surgery are factors that predict unplanned admission [ 14 , 35 , 54 ]. However, in our study, comorbidities and age greater than or equal to 65 years were not associated with unplanned overnight admission. Similar findings have been reported, where other authors have also found no association between comorbidities [ 35 ] and older age [ 14 ] with outpatient procedure failure. Our study observed that higher hospital volume (number of cases per year) was associated with decreased unplanned overnight admissions. This can be explained because more experienced surgeons achieve shorter procedure times and a lower rate of complications, which reduces the probability of unplanned overnight admissions. In the multivariable analysis, open surgery was independently associated with unplanned overnight admission. Therefore, a transition to laparoscopic surgery of the BIHR could increase the use of outpatient surgery and decrease the rate of unplanned admissions. This transition can be achieved safely and feasibly through a structured and systematic training process without an increase in complication or recurrence rates [ 58 ]. Our study has limitations inherent to clinical-administrative databases, including the absence of clinical data such as body mass index, surgical technique, surgical duration, reasons for unplanned overnight admission, and post-discharge clinical outcomes such as unplanned readmission to the hospital. Furthermore, potential underreporting may exist due to incomplete discharge reports or errors made during data recording by technical-administrative staff. However, the main strength of our study is its statistical power due to the large sample size. Previous studies have demonstrated the usefulness of clinical-administrative databases such as the RAE-CMBD for surgical research [ 46 , 59 – 62 ]. CONCLUSIONS The use of outpatient surgery for bilateral inguinal hernia in Spain has recently increased, although it remains low. Older age and comorbidities were associated with less use of outpatient surgery. However, laparoscopic repair was associated with increased outpatient surgery and a reduced rate of unplanned overnight admissions. Adopting less restrictive inclusion criteria and a transition to laparoscopic bilateral inguinal hernia repair could increase the rate of outpatient surgery. Declarations Competing Interests: The authors declare that they have no conflict of interest. Funding: Not applicable. Availability of data and materials: The datasets used and analyzed during the current study are available from the corresponding author on reasonable request. Authors’ Contributions Study conception and design were performed by Nils Jimmy Hidalgo, and Salvador Guillaumes. Acquisition of data was performed by Nils Jimmy Hidalgo, M. Magdalena Llompart-Coll, Paula González-Atienza, and Irene Bachero. Analysis and interpretation of data were performed by Nils Jimmy Hidalgo, M. Magdalena Llompart-Coll, and Salvador Guillaumes. Drafting of manuscript was performed by Nils Jimmy Hidalgo, M. Magdalena Llompart-Coll, and Salvador Guillaumes. Critical revision of manuscript was performed by Nils Jimmy Hidalgo, M. Magdalena Llompart-Coll, Salvador Guillaumes, Dulce Momblán, and Óscar Vidal. All authors read and approved the final manuscript. References Kingsnorth A, LeBlanc K (2003) Hernias: inguinal and incisional. 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Hernia 17:723–7. https://doi.org/10.1007/s10029-012-1040-0 Kurzer M, Kark A, Hussain ST (2009) Day-case inguinal hernia repair in the elderly: a surgical priority. Hernia 13:131–6. https://doi.org/10.1007/s10029-008-0452-3 Hajri M, Haddad D, Zaafouri H, et al (2022) Ambulatory hernia repair: a study of 1294 patients in a single institution. Pan Afr Med J 42:235. https://doi.org/10.11604/pamj.2022.42.235.32863 Palumbo P, Amatucci C, Perotti B, et al (2014) Outpatient repair for inguinal hernia in elderly patients: still a challenge? Int J Surg 12 Suppl 2:S4–S7. https://doi.org/10.1016/j.ijsu.2014.08.393 Canet J, Raeder J, Rasmussen LS, et al (2003) Cognitive dysfunction after minor surgery in the elderly. Acta Anaesthesiol Scand 47:1204–10. https://doi.org/10.1046/j.1399-6576.2003.00238.x American Society of Anesthesiologists (2021) ASA Physical Status Classification System. https://www.asahq.org/standards-and-guidelines/asa-physical-status-classification-system. Accessed 12 Mar 2022 Sanjay P, Jones P, Woodward A (2006) Inguinal hernia repair: are ASA grades 3 and 4 patients suitable for day case hernia repair? Hernia 10:299–302. https://doi.org/10.1007/s10029-005-0048-0 Solodkyy A, Feretis M, Fedotovs A, et al (2018) Elective “True Day Case” Laparoscopic Inguinal Hernia Repair in a District General Hospital: Lessons Learned from 1000 Consecutive Cases. Minim Invasive Surg 2018:7123754. https://doi.org/10.1155/2018/7123754 Drissi F, Gillion JF, Cossa JP, et al (2019) Factors of selection and failure of ambulatory incisional hernia repair: A cohort study of 1429 patients. J Visc Surg 156:85–90. https://doi.org/10.1016/j.jviscsurg.2018.07.001 Palumbo P, Minicucci A, Nasti AG, et al (2007) Treatment for persistent chronic neuralgia after inguinal hernioplasty. Hernia 11:527–31. https://doi.org/10.1007/s10029-007-0268-6 Pavlin DJ, Chen C, Penaloza DA, et al (2002) Pain as a factor complicating recovery and discharge after ambulatory surgery. Anesth Analg 95:627–34, table of contents. https://doi.org/10.1097/00000539-200209000-00025 Feliu-Palà X, Martín-Gómez M, Morales-Conde S, Fernández-Sallent E (2001) The impact of the surgeon’s experience on the results of laparoscopic hernia repair. Surg Endosc 15:1467–70. https://doi.org/10.1007/s00464-001-9017-6 Schmedt CG, Sauerland S, Bittner R (2005) Comparison of endoscopic procedures vs Lichtenstein and other open mesh techniques for inguinal hernia repair: a meta-analysis of randomized controlled trials. Surg Endosc 19:188–99. https://doi.org/10.1007/s00464-004-9126-0 Feliu X, Clavería R, Besora P, et al (2011) Bilateral inguinal hernia repair: laparoscopic or open approach? Hernia 15:15–8. https://doi.org/10.1007/s10029-010-0736-2 Memon MA, Cooper NJ, Memon B, et al (2003) Meta-analysis of randomized clinical trials comparing open and laparoscopic inguinal hernia repair. Br J Surg 90:1479–92. https://doi.org/10.1002/bjs.4301 Rosenberg J, Friis-Andersen H, Jørgensen LN, Andresen K (2021) Variables in the Danish Hernia Databases: inguinal and ventral. Laparosc Surg 5:30–30. https://doi.org/10.21037/ls-20-125 Madion M, Goldblatt MI, Gould JC, Higgins RM (2021) Ten-year trends in minimally invasive hernia repair: a NSQIP database review. Surg Endosc 35:7200–7208. https://doi.org/10.1007/s00464-020-08217-9 Palser TR, Swift S, Williams RN, et al (2019) Variation in outcomes and use of laparoscopy in elective inguinal hernia repair. BJS Open 3:466–475. https://doi.org/10.1002/bjs5.50158 Guillaumes S, Hoyuela C, Hidalgo NJ, et al (2021) Inguinal hernia repair in Spain. A population-based study of 263,283 patients: factors associated with the choice of laparoscopic approach. Hernia 25:1345–1354. https://doi.org/10.1007/s10029-021-02402-y Andresen K, Rosenberg J (2021) Decreasing use of open procedures in elective inguinal hernia surgery. Laparosc Surg 5:17–17. https://doi.org/10.21037/ls-20-126 Bittner R, Montgomery MA, Arregui E, et al (2015) Update of guidelines on laparoscopic (TAPP) and endoscopic (TEP) treatment of inguinal hernia (International Endohernia Society). Surg Endosc 29:289–321. https://doi.org/10.1007/s00464-014-3917-8 Poelman MM, van den Heuvel B, Deelder JD, et al (2013) EAES Consensus Development Conference on endoscopic repair of groin hernias. Surg Endosc 27:3505–19. https://doi.org/10.1007/s00464-013-3001-9 Simons MP, Aufenacker T, Bay-Nielsen M, et al (2009) European Hernia Society guidelines on the treatment of inguinal hernia in adult patients. Hernia 13:343–403. https://doi.org/10.1007/s10029-009-0529-7 Bittner R, Arregui ME, Bisgaard T, et al (2011) Guidelines for laparoscopic (TAPP) and endoscopic (TEP) treatment of inguinal hernia [International Endohernia Society (IEHS)]. Surg Endosc 25:2773–843. https://doi.org/10.1007/s00464-011-1799-6 Hidalgo NJ, Guillaumes S, Bachero I, et al (2023) Trends and predictors of laparoscopic bilateral inguinal hernia repair in Spain: a population-based study. Surg Endosc 37:4784–4794. https://doi.org/10.1007/s00464-023-09967-y Trevisonno M, Kaneva P, Watanabe Y, et al (2015) A survey of general surgeons regarding laparoscopic inguinal hernia repair: practice patterns, barriers, and educational needs. Hernia 19:719–24. https://doi.org/10.1007/s10029-014-1287-8 Whippey A, Kostandoff G, Paul J, et al (2013) Predictors of unanticipated admission following ambulatory surgery: a retrospective case-control study. Can J Anaesth 60:675–83. https://doi.org/10.1007/s12630-013-9935-5 Kingsnorth AN, Bowley DMG, Porter C (2003) A prospective study of 1000 hernias: results of the Plymouth Hernia Service. Ann R Coll Surg Engl 85:18–22. https://doi.org/10.1308/003588403321001363 Van Caelenberg E, De Regge M, Eeckloo K, Coppens M (2019) Analysis of failed discharge after ambulatory surgery: unanticipated admission. Acta Chir Belg 119:139–145. https://doi.org/10.1080/00015458.2018.1477488 Ngo P, Pélissier E, Levard H, et al (2010) Ambulatory groin and ventral hernia repair. J Visc Surg 147:e325-8. https://doi.org/10.1016/j.jviscsurg.2010.09.003 Hidalgo NJ, Bachero I, Hoyuela C, et al (2022) The transition from open to laparoscopic surgery for bilateral inguinal hernia repair: how we did it. Langenbecks Arch Surg 407:3701–3710. https://doi.org/10.1007/s00423-022-02671-w Guillaumes S, Juvany M (2022) Inguinal hernia repairs performed for recurrence in Spain: population-based study of 16 years and 1,302,788 patients. Hernia 26:1023–1032. https://doi.org/10.1007/s10029-022-02630-w Trevisonno M, Kaneva P, Watanabe Y, et al (2015) Current practices of laparoscopic inguinal hernia repair: a population-based analysis. Hernia 19:725–33. https://doi.org/10.1007/s10029-015-1358-5 Muaddi H, Stukel TA, de Mestral C, et al (2023) The evolving use of robotic surgery: a population-based analysis. Surg Endosc 37:1870–1877. https://doi.org/10.1007/s00464-022-09643-7 Smith FJ, Holman CDJ, Moorin RE, Fletcher DR (2008) Incidence of bariatric surgery and postoperative outcomes: a population-based analysis in Western Australia. Med J Aust 189:198–202. https://doi.org/10.5694/j.1326-5377.2008.tb01981.x Additional Declarations No competing interests reported. Supplementary Files Supplementarymaterial.docx Cite Share Download PDF Status: Under Review Version 1 posted Reviews received at journal 21 Dec, 2023 Reviewers agreed at journal 13 Dec, 2023 Reviewers agreed at journal 11 Dec, 2023 Reviewers invited by journal 11 Dec, 2023 Submission checks completed at journal 21 Nov, 2023 First submitted to journal 21 Nov, 2023 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-3576250","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":262196492,"identity":"aabe650c-4eb9-4691-bc68-dd073a0df358","order_by":0,"name":"Nils Jimmy Hidalgo","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAwklEQVRIiWNgGAWjYDACZuYGZgYGmwQwJ6GAKC2MIC1pCQxsIC0GRFkD1nIYooWBGC3m7IzNnwv3nM/jl+9O/PDAgEGeX+wAfi2WzYxt0jOe3S6WbOPdLAF0mOHM2Qn4tRgcZmxj5jlwO3HDMd4NIC0JBrcJa2n+zHPgHEjL5h/EammQ5jlwAKRlG9G2tAG1JCfObMvdZpFgIEGEX84fPgx0mF1iP/PZzTd/VNjI80sT0IIOJEhTPgpGwSgYBaMAOwAA5IlCcbfkakUAAAAASUVORK5CYII=","orcid":"","institution":"Hospital Clínic de Barcelona","correspondingAuthor":true,"prefix":"","firstName":"Nils","middleName":"Jimmy","lastName":"Hidalgo","suffix":""},{"id":262196493,"identity":"20a6df48-da1b-4329-83c8-5dee0e2139ee","order_by":1,"name":"Salvador Guillaumes","email":"","orcid":"","institution":"Hospital Clínic de Barcelona","correspondingAuthor":false,"prefix":"","firstName":"Salvador","middleName":"","lastName":"Guillaumes","suffix":""},{"id":262196494,"identity":"ff00c162-92ce-478c-9053-13ec95b80c72","order_by":2,"name":"M. Magdalena Llompart-Coll","email":"","orcid":"","institution":"Hospital Clínic de Barcelona","correspondingAuthor":false,"prefix":"","firstName":"M.","middleName":"Magdalena","lastName":"Llompart-Coll","suffix":""},{"id":262196495,"identity":"f28ecb0e-5d22-4aea-90fd-0bad2ee6c9c6","order_by":3,"name":"Paula González-Atienza","email":"","orcid":"","institution":"Hospital Clínic de Barcelona","correspondingAuthor":false,"prefix":"","firstName":"Paula","middleName":"","lastName":"González-Atienza","suffix":""},{"id":262196496,"identity":"187c94bf-e60d-4ec4-8152-68bf16ed9f40","order_by":4,"name":"Irene Bachero","email":"","orcid":"","institution":"Hospital Clínic de Barcelona","correspondingAuthor":false,"prefix":"","firstName":"Irene","middleName":"","lastName":"Bachero","suffix":""},{"id":262196497,"identity":"04fdbe81-fe9c-4059-8b57-d93a84f73fb0","order_by":5,"name":"Dulce Momblán","email":"","orcid":"","institution":"Hospital Clínic de Barcelona","correspondingAuthor":false,"prefix":"","firstName":"Dulce","middleName":"","lastName":"Momblán","suffix":""},{"id":262196498,"identity":"c8c72cfb-6ffb-4d8c-ba41-28939823b3cd","order_by":6,"name":"Óscar Vidal","email":"","orcid":"","institution":"Hospital Clínic de Barcelona","correspondingAuthor":false,"prefix":"","firstName":"Óscar","middleName":"","lastName":"Vidal","suffix":""}],"badges":[],"createdAt":"2023-11-07 20:14:11","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-3576250/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-3576250/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":55009044,"identity":"89e2c8fb-d53f-4ccf-97ff-f6b2fe4d1510","added_by":"auto","created_at":"2024-04-19 19:11:20","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":39859,"visible":true,"origin":"","legend":"\u003cp\u003eCase Selection Flow Chart\u003cbr\u003e\n \u003cem\u003eIHR: Inguinal hernia repair\u003cbr\u003e\nIDC-10: 10th revision of the International Statistical Classification of Diseases\u003c/em\u003e\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-3576250/v1/3226d10e4c652d07c6263b6c.png"},{"id":55009043,"identity":"7c6c6ff1-b58b-4e59-bca0-d9ebce4de480","added_by":"auto","created_at":"2024-04-19 19:11:20","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":44328,"visible":true,"origin":"","legend":"\u003cp\u003eThe outpatient surgery rate in bilateral inguinal hernia repair. Cochran-Armitage test for trend was significant (\u003cem\u003ep\u003c/em\u003e\u0026lt;0.001)\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-3576250/v1/7ad14bb2e15a87a6d8f4bd87.png"},{"id":55009047,"identity":"ce3030f0-98b2-4e9c-be8e-07878b85cbb6","added_by":"auto","created_at":"2024-04-19 19:11:20","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":36197,"visible":true,"origin":"","legend":"\u003cp\u003eThe outpatient surgery rate of bilateral inguinal hernia repair by hospital volume. Cochran-Armitage test for trend was significant (\u003cem\u003ep\u003c/em\u003e\u0026lt;0.001)\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-3576250/v1/b3a8404c829de5c263ae35ed.png"},{"id":55010538,"identity":"aa737799-5a01-4f25-9347-729a2ef2cc70","added_by":"auto","created_at":"2024-04-19 19:27:20","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":504251,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-3576250/v1/5aedcb8f-29c5-4958-8ccf-d638c1a18c1e.pdf"},{"id":55010361,"identity":"ac0277e3-3ade-4e09-828a-165adaf1f781","added_by":"auto","created_at":"2024-04-19 19:19:20","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":14892,"visible":true,"origin":"","legend":"","description":"","filename":"Supplementarymaterial.docx","url":"https://assets-eu.researchsquare.com/files/rs-3576250/v1/b4f7d20cc23850d0639e095d.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Outpatient surgery and unplanned overnight admission in bilateral inguinal hernia repair: a population-based study","fulltext":[{"header":"INTRODUCTION","content":"\u003cp\u003eInguinal hernia is a common surgical issue accounting for 75% of all abdominal wall hernias [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e] and Inguinal hernia repair ranks among the most frequently conducted surgical interventions worldwide [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. As such, changes in the type of hospitalization, utilization of minimally invasive surgical techniques, and rate of postoperative complications of inguinal hernia surgery can significantly impact the healthcare system.\u003c/p\u003e \u003cp\u003eAdvances in surgical and anesthetic techniques have increased the proportion of inguinal hernia repairs conducted as outpatient surgery [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Outpatient surgery offers several advantages, including early mobilization, increased patient satisfaction, decreased susceptibility to nosocomial infections and venous thromboembolism, and minimized costs associated with conventional inpatient care [\u003cspan additionalcitationids=\"CR6 CR7\" citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eNevertheless, the outpatient inguinal hernia repair rate remains variable despite its wide acceptance and international clinical guideline recommendation [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Patient characteristics, surgeon preferences, and health system incentives influence its choice. It is recommended that over 70% of adult inguinal hernia repairs should be conducted as outpatient surgery [\u003cspan additionalcitationids=\"CR11\" citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eSome authors suggest that bilateral inguinal hernias should preferably receive hospital treatment due to the increased risk of perioperative complications [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. In addition, bilateral inguinal hernia has been described as a predictor of ambulatory failure [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. However, according to other studies, bilateral inguinal hernia is not a limitation for outpatient surgery and is not associated with an increased risk of failure [\u003cspan additionalcitationids=\"CR16\" citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. Limited research exists on outpatient surgery utilization for inguinal hernia, and no specific studies exist on bilateral inguinal hernia.\u003c/p\u003e \u003cp\u003eThis study aimed to analyze the utilization trend of outpatient surgery for BHIR in Spain, identify the factors associated with the choice of outpatient surgery, and the factors associated with unplanned overnight admission in patients initially scheduled for outpatient surgery.\u003c/p\u003e"},{"header":"MATERIALS AND METHODS","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStudy design\u003c/h2\u003e \u003cp\u003eA retrospective observational study was conducted using the Hospital Discharge Registry of the Spanish Ministry of Health (Registro de Actividad de Atenci\u0026oacute;n Especializada-Conjunto M\u0026iacute;nimo B\u0026aacute;sico de Datos, RAE-CMBD) [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. In Spain, the RAE-CMBD is a mandatory registry of the diagnoses and healthcare procedures performed in all public and private hospitals nationwide, using the International Classification of Diseases Version 10 (ICD-10) codes. The data is obtained from the information in each patient's discharge report. It records three types of variables: patient identification, identification of the care episode, and clinical variables. The physician completes the hospital discharge information in the discharge report, and subsequently, the health coding specialist performs the coding of the information contained in the hospital discharge report.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eStudy population\u003c/h2\u003e \u003cp\u003eOur study included patients who underwent BIHR in the Spanish National Health System hospitals from 2016 to 2021. The flowchart (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e) shows the ICD-10 diagnostic codes used to identify patients.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eInclusion criteria: 1) Patients with main BIHR procedure and 2) Age greater than or equal to 15 years.\u003c/p\u003e \u003cp\u003eExclusion criteria: 1) Manual reduction of the hernia and 2) Emergency or unscheduled care.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eVariables analyzed\u003c/h2\u003e \u003cdiv id=\"Sec6\" class=\"Section3\"\u003e \u003ch2\u003eDemographic characteristics and comorbidities\u003c/h2\u003e \u003cp\u003eData analysis included age, sex, and comorbidities. The specific comorbidities were identified using ICD-10 diagnostic codes described by Quan et al. [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. The specific comorbidities considered included arterial hypertension, heart disease, chronic lung disease, renal disease, liver disease, diabetes mellitus, obesity, peripheral vascular disease, cerebrovascular disease, rheumatic disease, and alcohol and tobacco abuse. Charlson and Elixhauser comorbidity indices were calculated for each patient. Supplementary material presents the ICD-10 codes used for comorbidities.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section3\"\u003e \u003ch2\u003eHospital volume\u003c/h2\u003e \u003cp\u003eThe study analyzed the relation between the outpatient surgery rate and hospital volume, which was defined as the number of BIHRs performed by year.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec8\" class=\"Section3\"\u003e \u003ch2\u003eCharacteristics of the hernia and surgery\u003c/h2\u003e \u003cp\u003eThe pre-surgical presence of recurrent hernia and complicated hernia was recorded. The complicated hernia was defined as obstruction or gangrene in the diagnostic code. The surgical approach, open or laparoscopic, was recorded.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec9\" class=\"Section3\"\u003e \u003ch2\u003eOutpatient surgery\u003c/h2\u003e \u003cp\u003ePatients scheduled for inpatient and outpatient surgery for BIHR were identified. We used the variable \"type of contact\" from the RAE-CMBD database to identify patients initially scheduled for outpatient surgery. A comparative analysis between the two groups was conducted, and a multivariable analysis was performed to determine the factors associated with the choice of outpatient surgery.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec10\" class=\"Section3\"\u003e \u003ch2\u003eUnplanned overnight admission\u003c/h2\u003e \u003cp\u003eThe unplanned overnight admission and unplanned readmission rate to the hospital are quality markers for ambulatory surgery units. Patients who required unplanned overnight admission among those initially scheduled for outpatient surgery were identified. Unplanned overnight admission was defined as a hospital stay lasting\u0026thinsp;\u0026ge;\u0026thinsp;1 day.\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analysis\u003c/h2\u003e \u003cp\u003eThe Chi-square test was used for the qualitative variables. For quantitative variables with normal distribution, Student's t-test was used to compare between two groups. For non-normal distributions, the non-parametric Mann-Whitney U test was used.\u003c/p\u003e \u003cp\u003eThe Cochran-Armitage test was used for trend analysis of ordinal categorical variables,\u003c/p\u003e \u003cp\u003eA multivariable logistic regression analysis was performed to identify factors associated with the choice of outpatient surgery and to identify factors associated with unplanned overnight admission.\u003c/p\u003e \u003cp\u003eStatistical significance was set at p\u0026thinsp;\u0026lt;\u0026thinsp;0.05. IBM SPSS 27.0 software (Armonk, NY: IBM Corp) was used for statistical analysis.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003eEthical aspects\u003c/h2\u003e \u003cp\u003eThe analyzed data is anonymous and sourced from a database under the management of the Spanish Ministry of Health, adhering to the data protection regulations in Spain. Identifying patients at the individual or reporting unit level is impossible, and using information from clinical-administrative bases does not require the approval of a Medical Research Ethics Committee.\u003c/p\u003e \u003c/div\u003e"},{"header":"RESULTS","content":"\u003cdiv id=\"Sec14\" class=\"Section2\"\u003e \u003ch2\u003eUtilization trend of outpatient surgery in BIHR\u003c/h2\u003e \u003cp\u003eOur study included 30,940 BIHR, 19,452 (63%) as inpatient surgeries, and 11,488 (37%) as outpatient surgeries. Over the analyzed period, there was a statistically significant upward trend in the utilization of outpatient surgery in the test of Cochran-Armitage (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), increasing from 30% in 2016 to 41% in 2021 (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec15\" class=\"Section2\"\u003e \u003ch2\u003eHospital volume\u003c/h2\u003e \u003cp\u003eThe outpatient surgery utilization rate was proportionally higher (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) in hospitals with the highest number of BIHRs performed per year (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec16\" class=\"Section2\"\u003e \u003ch2\u003eDemographic characteristics and comorbidity\u003c/h2\u003e \u003cp\u003eThe mean age was higher in the inpatient surgery group than in the outpatient surgery group (63.58\u0026thinsp;\u0026plusmn;\u0026thinsp;13.29 vs. 58.22\u0026thinsp;\u0026plusmn;\u0026thinsp;12.99, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), and there were no significant differences in sex between the two groups (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). The comorbidities were higher in inpatient surgery group with a significant difference (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001).\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\u003eCharacteristics of the patients with bilateral inguinal hernia repair (2016\u0026ndash;2021)\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=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003cp\u003eN\u0026thinsp;=\u0026thinsp;30,940\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eInpatient N\u0026thinsp;=\u0026thinsp;19,452\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eOutpatient N\u0026thinsp;=\u0026thinsp;11,488\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\u003eAge, Mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e61.59\u0026thinsp;\u0026plusmn;\u0026thinsp;13.43\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e63.58\u0026thinsp;\u0026plusmn;\u0026thinsp;13.29\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e58.22\u0026thinsp;\u0026plusmn;\u0026thinsp;12.99\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\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\u003eAge\u0026thinsp;\u0026lt;\u0026thinsp;65 years, N (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e17,285 (55.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e9,652 (49.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e7,633 (66.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\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\u003eAge\u0026thinsp;\u0026ge;\u0026thinsp;65 years, N (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e13,655 (44.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e9,800 (50,4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3,855 (33.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\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, N (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.942\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e28,682 (92.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e18,034 (92.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e10,648 (92.7)\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\u003eFemale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2,258 (7.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1,418 (7.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e840 (7.3)\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\u003eComorbidities, N (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\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\u003eArterial hypertension\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8,030 (26)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6,594 (33.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1,436 (12.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\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\u003eHeart disease\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2,448 (7.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2,203 (11.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e245 (2.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\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\u003eChronic pulmonary disease\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1,874 (6.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1,543 (7.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e331 (2.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\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\u003eRenal disease\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e559 (1.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e496 (2.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e63 (0.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\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\u003eLiver disease\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e517 (1.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e410 (2.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e107 (0.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\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\u003eDiabetes mellitus\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2,606 (8.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2,137 (11)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e469 (4.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\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\u003eObesity\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e857 (2.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e649 (3.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e208 (1.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\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\u003ePeripheral vascular disease\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e387 (1.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e355 (1.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e32 (0.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\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\u003eCerebrovascular disease\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e162 (0.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e142 (0.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e20 (0.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\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\u003eRheumatic disease\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e240 (0.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e198 (1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e42 (0.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\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\u003eAlcohol abuse\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e640 (2.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e491 (2.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e149 (1.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\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\u003eTobacco use\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3,883 (12.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2893 (14.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e990 (8.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\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\u003eCharlson Index, Mean (SD)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.3\u0026thinsp;\u0026plusmn;\u0026thinsp;0.76\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.4\u0026thinsp;\u0026plusmn;\u0026thinsp;0.89\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.12\u0026thinsp;\u0026plusmn;\u0026thinsp;0.47\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\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\u003eElixhauser Index, Mean (SD)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.76\u0026thinsp;\u0026plusmn;\u0026thinsp;2.75\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.07\u0026thinsp;\u0026plusmn;\u0026thinsp;3.17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.23\u0026thinsp;\u0026plusmn;\u0026thinsp;1.71\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\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\u003eHernia characteristics, N (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\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\u003eRecurrent hernia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2,271 (7.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1,712 (8.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e559 (4.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\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\u003ePrimary hernia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e28,669 (92.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e17,740 (91.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e10,929 (95.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\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\u003eSurgery approach, N (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\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\u003eOpen surgery\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e24,524 (79.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e15,887 (81.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e8,637 (75.2)\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\u003eLaparoscopy surgery\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6,416 (20.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3,565 (18.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2,851 (24.8)\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\u003eHospital volume, N (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\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\u003e1\u0026ndash;20 cases/year\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e10,795 (34.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7,205 (37)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3,590 (31.3)\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\u003e20\u0026ndash;40 cases/year\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e12,907 (41.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8,170 (42)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4,737 (41.2)\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\u003e40\u0026ndash;60 cases/year\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4,462 (14.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2,617 (13.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1,845 (16.1)\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\u003e60\u0026ndash;80 cases/year\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e863 (2.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e560 (2.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e303 (2.6)\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\u003e\u0026gt;80 cases/year\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1,913 (6.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e900 (4.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1,013 (8.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003e\u003cem\u003eSD: standard deviation\u003c/em\u003e\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec17\" class=\"Section2\"\u003e \u003ch2\u003eCharacteristics of the hernia and surgery\u003c/h2\u003e \u003cp\u003eThe proportion of recurrent hernia was higher in the inpatient surgery group (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). The use of laparoscopic surgery was higher in the outpatient surgery group than in the inpatient surgery group (24.8% vs 18.3%, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec18\" class=\"Section2\"\u003e \u003ch2\u003eFactors associated with the use of outpatient surgery\u003c/h2\u003e \u003cp\u003eIn the multivariable logistic regression analysis, the factors independently associated with the choice of outpatient surgery were: age under 65 years (OR: 2.01, 95% CI: 1.92\u0026ndash;2.11), hospital volume\u0026thinsp;\u0026gt;\u0026thinsp;60 cases/year (OR: 1.59, 95% CI: 1.47\u0026ndash;1.72), primary inguinal hernia (OR: 1.89, 95% CI: 1.71\u0026ndash;2.08), and laparoscopic surgery (OR: 1.47, 95% CI: 1.39\u0026ndash;1.56). The comorbidities presented a negative association with the choice of outpatient surgery (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\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\u003eUnivariable and multivariable analysis of factors associated with the choice of outpatient bilateral inguinal hernia repair.\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\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eUnivariable analysis\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e \u003cp\u003eMultivariable analysis\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eOR (95% CI)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ep-value\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eOR (95% CI)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003ep-value\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge\u0026thinsp;\u0026lt;\u0026thinsp;65 years\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.01 (1.92\u0026ndash;2.11)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.34 (1.27\u0026ndash;1.41)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\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\u003e1.01 (0.92\u0026ndash;1.09)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.942\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\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\u003eHospital volume\u0026thinsp;\u0026gt;\u0026thinsp;60 cases/year\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.59 (1.47\u0026ndash;1.72)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.59 (1.46\u0026ndash;1.72)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\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\u003ePrimary hernia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.89 (1.71\u0026ndash;2.08)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.78 (1,61-1.97)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\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\u003eArterial hypertension\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.28 (0.27\u0026ndash;0.29)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.41 (0.38\u0026ndash;0.44)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\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\u003eHeart disease\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.17 (0.15\u0026ndash;0.19)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.31 (0.29\u0026ndash;0.36)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\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\u003eChronic pulmonary disease\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.34 (0.31\u0026ndash;0.39)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.51 (0.45\u0026ndash;0.58)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\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\u003eRenal disease\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.21 (0.16\u0026ndash;0.27)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.59 (0.45\u0026ndash;0.78)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLiver disease\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.44 (0.35\u0026ndash;0.54)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.59 (0.47\u0026ndash;0.73)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\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\u003eDiabetes mellitus\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.35 (0.31\u0026ndash;0.38)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.64 (0.58\u0026ndash;0.72)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\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\u003eObesity\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.53 (0.46\u0026ndash;0.63)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.79 (0.67\u0026ndash;0.93)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.005\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePeripheral vascular disease\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.15 (0.11\u0026ndash;0.22)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.35 (0.24\u0026ndash;0.51)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\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\u003eCerebrovascular disease\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.24 (0.15\u0026ndash;0.38)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.37 (0.32\u0026ndash;0.86)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.01\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRheumatic disease\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.53 (0.26\u0026ndash;0.49)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.53 (0.37\u0026ndash;0.75)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\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\u003eLaparoscopic surgery\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.47 (1.39\u0026ndash;1.56)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.31 (1.24\u0026ndash;1.39)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003e\u003cem\u003eOR: odds ratio, CI: confidence interval.\u003c/em\u003e\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec19\" class=\"Section2\"\u003e \u003ch2\u003eUnplanned overnight admission\u003c/h2\u003e \u003cp\u003eAmong the 11,488 patients initially scheduled for outpatient surgery, 1143 (9.9%) required an unplanned overnight admission. In this study, open surgery was independently associated (OR: 1.26, 95% CI: 1.09\u0026ndash;1.47) with unplanned overnight admission, while hospital volume\u0026thinsp;\u0026gt;\u0026thinsp;60 cases/year was negatively associated (OR: 0.16, 95% CI: 0.11\u0026ndash;0.24) with unplanned overnight admission (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\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\u003eUnivariable and multivariable analysis of factors associated with unplanned overnight admissions of outpatient bilateral inguinal hernia repair.\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\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eUnivariable analysis\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e \u003cp\u003eMultivariable analysis\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eOR (95% CI)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ep-value\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eOR (95% CI)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003ep-value\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge\u0026thinsp;\u0026ge;\u0026thinsp;65 years\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.91 (0.79\u0026ndash;1.03)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.137\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\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\u003eSex Male\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.92 (0.72\u0026ndash;1.17)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.504\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\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\u003eHospital volume\u0026thinsp;\u0026gt;\u0026thinsp;60 cases/year\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.16 (0.11\u0026ndash;0.24)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.17 (0.11\u0026ndash;0.24)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\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\u003eRecurrent hernia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.2 (0.92\u0026ndash;1.57)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.175\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\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\u003eArterial hypertension\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.49 (0.94\u0026ndash;2.38)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.091\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\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\u003eHeart disease\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.27 (0.86\u0026ndash;1.87)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.226\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\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\u003eChronic pulmonary disease\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.89 (0.62\u0026ndash;1.32)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.585\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\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\u003eRenal disease\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.15 (0.02\u0026ndash;1.05)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.056\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\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\u003eLiver disease\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.93 (0.49\u0026ndash;1.79)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.834\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\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\u003eDiabetes mellitus\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.79 (0.56\u0026ndash;1.11)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.173\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\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\u003eObesity\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.75 (0.45\u0026ndash;1.26)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.274\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\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\u003ePeripheral vascular disease\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.29 (0.04\u0026ndash;2.14)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.225\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\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\u003eCerebrovascular disease\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.48 (0.07\u0026ndash;3.56)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.469\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\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\u003eRheumatic disease\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.95 (0.34\u0026ndash;2.67)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.926\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\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\u003eOpen surgery\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.26 (1.09\u0026ndash;1.47)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.002\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.23 (1.06\u0026ndash;1.43)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.007\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003e\u003cem\u003eOR: odds ratio, CI: confidence interval.\u003c/em\u003e\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"DISCUSSION","content":"\u003cp\u003eThe use of outpatient surgery for BIHR has increased in recent years. Factors such as age below 65 years, larger hospital volume, primary inguinal hernia, and laparoscopic approach were associated with the choice of outpatient surgery. Conversely, comorbidities showed a negative association. Furthermore, open surgery was independently linked to unplanned overnight admission.\u003c/p\u003e \u003cp\u003eThe advantages of outpatient inguinal hernia surgery are widely recognized, including higher patient satisfaction rates and reduced costs [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. Hospital-admitted inguinal hernia surgery costs 56% more than outpatient surgery [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. Additionally, it enables better utilization of hospital resources by ensuring beds are available for patients with more severe conditions.\u003c/p\u003e \u003cp\u003eThe utilization of outpatient surgery for inguinal hernia repair has increased globally [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e, \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. However, the proportion of use varies significantly across countries. Some countries have achieved high utilization rates exceeding 70%. Rates of 70% were reported in Denmark [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e] and 74% in France [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. In a study conducted in hospitals in northeast Italy, the rate was even higher at 76% [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. While in other countries, such as Germany, the proportion of outpatient surgery in inguinal hernia repair was only 14% in 2019 [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. A recent study in Spain reported that 54% of all inguinal hernia repairs were performed as outpatient procedures [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. The variability in outpatient surgery utilization can be attributed to differences in patient selection criteria and economic incentives for hospitals and surgeons to promote outpatient surgeries [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. The number of procedures performed by outpatient surgery in Spain could be greater through the application of measures by the National Health System that encourage hospitals to increase the use of outpatient surgery to optimize public health resources. In our analysis of bilateral hernias, we observed an increasing trend in outpatient surgery, from 30% in 2016 to 41% in 2021. In 2020, we observed an increase in the use of outpatient surgery up to 43%, probably influenced by the COVID-19 pandemic. However, the use of outpatient surgery in 2021 was 41%. Future studies are necessary to analyze whether the trend toward increased use of outpatient surgery observed during the year of the COVID-19 pandemic will continue in the coming years.\u003c/p\u003e \u003cp\u003eThe patient's age has been considered by some authors as a criterion for selecting candidates for outpatient surgery in inguinal hernia repair [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e, \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]. Our study found that age under 65 was independently associated with the choice of outpatient surgery. However, other studies have shown that older patients do not have higher complication rates than younger patients [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e, \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e], suggesting that age should not be a contraindication for outpatient surgery [\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e, \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e]. Including elderly patients in outpatient surgery can increase utilization rates and provide them with the benefits of a shorter hospital stay, such as reduced cognitive impairment [\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eOur study found that comorbidities were negatively associated with the choice of outpatient surgery for BIHR. The Spanish Ministry of Health uses the classification of the American Society of Anesthesiologists (ASA) [\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e] in its recommendations for selecting candidate patients for outpatient surgery. It considers suitable patients with ASA 1, ASA 2, and ASA 3 without decompensation. However, studies conducted in inguinal hernia surgery suggest that comorbidities or the ASA score should not be a contraindication for outpatient surgery [\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e, \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e]. Utilizing outpatient surgery in patients with comorbidities could offer them the advantages of reduced risk for nosocomial infections and venous thromboembolic complications, to which they are more vulnerable [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe characteristics of the hernia can play a role in determining the suitability of outpatient surgery. Strangulated hernia and large inguinoscrotal hernia have been considered exclusion criteria in some studies [\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e]. However, some authors argue that recurrent hernia should not be a contraindication for outpatient surgery [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. In our study, we found that recurrent hernia was negatively associated with the choice of outpatient surgery.\u003c/p\u003e \u003cp\u003eHospitals with higher case volumes and experienced surgeons tend to have shorter surgical times and lower complication rates [\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e]. These favorable outcomes are conducive to the implementation of outpatient surgery. In our study, we found that hospitals with a higher number of cases performed annually were more likely to choose outpatient surgery.\u003c/p\u003e \u003cp\u003eDecreased postoperative pain is one of the main factors that favor outpatient surgery [\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e], and it is known that laparoscopic inguinal hernia repair is associated with reduced postoperative pain, faster recovery, and fewer complications [\u003cspan additionalcitationids=\"CR40 CR41\" citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e]. However, the utilization rates are variable: 61% in Denmark [\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e], 38% in the USA [\u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e], 23% in England [\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e] and 5.7% in Spain [\u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e]. The high rate of use of laparoscopy in countries such as Denmark, where it reaches up to 96% in bilateral hernias [\u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e47\u003c/span\u003e], could be related to the high rates of use of outpatient surgery. The benefits of laparoscopic are greater in a bilateral inguinal hernia, and international clinical guidelines recommend performing BIHR using a laparoscopic approach [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan additionalcitationids=\"CR49 CR50\" citationid=\"CR48\" class=\"CitationRef\"\u003e48\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR51\" class=\"CitationRef\"\u003e51\u003c/span\u003e]. Our study observed that laparoscopic repair was independently associated with the choice of outpatient surgery. However, despite these advantages, the utilization rate of laparoscopic bilateral inguinal hernia repair in Spain remains low, with a reported rate of 23% in 2019 [\u003cspan citationid=\"CR52\" class=\"CitationRef\"\u003e52\u003c/span\u003e]. Efforts to increase the laparoscopic BIHR rate could increase outpatient surgery utilization in these patients. Furthermore, although the higher cost of laparoscopic surgery is a limiting factor [\u003cspan citationid=\"CR53\" class=\"CitationRef\"\u003e53\u003c/span\u003e], the cost-effectiveness of outpatient surgery would offset this expense.\u003c/p\u003e \u003cp\u003eThe rate of unplanned admissions in ambulatory inguinal hernia surgery varies considerably in the literature, ranging from 0\u0026ndash;19% [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e, \u003cspan additionalcitationids=\"CR55 CR56\" citationid=\"CR54\" class=\"CitationRef\"\u003e54\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR57\" class=\"CitationRef\"\u003e57\u003c/span\u003e]. In our study, we observed an unplanned overnight admission rate of 9.9%. Several published studies have been performed to identify predictors of unplanned admission to improve the outcomes of outpatient surgery for inguinal hernia. Some have identified ASA grades 3 and 4 as predictors of unplanned admission [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR54\" class=\"CitationRef\"\u003e54\u003c/span\u003e, \u003cspan citationid=\"CR56\" class=\"CitationRef\"\u003e56\u003c/span\u003e]. Other studies found that older patients, body mass index greater than 30, spinal anesthesia, and longer duration of surgery are factors that predict unplanned admission [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e, \u003cspan citationid=\"CR54\" class=\"CitationRef\"\u003e54\u003c/span\u003e]. However, in our study, comorbidities and age greater than or equal to 65 years were not associated with unplanned overnight admission. Similar findings have been reported, where other authors have also found no association between comorbidities [\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e] and older age [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e] with outpatient procedure failure. Our study observed that higher hospital volume (number of cases per year) was associated with decreased unplanned overnight admissions. This can be explained because more experienced surgeons achieve shorter procedure times and a lower rate of complications, which reduces the probability of unplanned overnight admissions.\u003c/p\u003e \u003cp\u003eIn the multivariable analysis, open surgery was independently associated with unplanned overnight admission. Therefore, a transition to laparoscopic surgery of the BIHR could increase the use of outpatient surgery and decrease the rate of unplanned admissions. This transition can be achieved safely and feasibly through a structured and systematic training process without an increase in complication or recurrence rates [\u003cspan citationid=\"CR58\" class=\"CitationRef\"\u003e58\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eOur study has limitations inherent to clinical-administrative databases, including the absence of clinical data such as body mass index, surgical technique, surgical duration, reasons for unplanned overnight admission, and post-discharge clinical outcomes such as unplanned readmission to the hospital. Furthermore, potential underreporting may exist due to incomplete discharge reports or errors made during data recording by technical-administrative staff. However, the main strength of our study is its statistical power due to the large sample size. Previous studies have demonstrated the usefulness of clinical-administrative databases such as the RAE-CMBD for surgical research [\u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e, \u003cspan additionalcitationids=\"CR60 CR61\" citationid=\"CR59\" class=\"CitationRef\"\u003e59\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR62\" class=\"CitationRef\"\u003e62\u003c/span\u003e].\u003c/p\u003e"},{"header":"CONCLUSIONS","content":"\u003cp\u003eThe use of outpatient surgery for bilateral inguinal hernia in Spain has recently increased, although it remains low. Older age and comorbidities were associated with less use of outpatient surgery. However, laparoscopic repair was associated with increased outpatient surgery and a reduced rate of unplanned overnight admissions. Adopting less restrictive inclusion criteria and a transition to laparoscopic bilateral inguinal hernia repair could increase the rate of outpatient surgery.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eCompeting Interests:\u0026nbsp;\u003c/strong\u003eThe authors declare that they have no conflict of interest.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding:\u0026nbsp;\u003c/strong\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials:\u0026nbsp;\u003c/strong\u003eThe datasets used and analyzed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; Contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eStudy conception and design were performed by Nils Jimmy Hidalgo, and Salvador Guillaumes. Acquisition of data was performed by Nils Jimmy Hidalgo, M. Magdalena Llompart-Coll, Paula Gonz\u0026aacute;lez-Atienza, and Irene Bachero. Analysis and interpretation of data were performed by Nils Jimmy Hidalgo, M. Magdalena Llompart-Coll, and Salvador Guillaumes. Drafting of manuscript was performed by Nils Jimmy Hidalgo, M. Magdalena Llompart-Coll, and Salvador Guillaumes. Critical revision of manuscript was performed by Nils Jimmy Hidalgo, M. Magdalena Llompart-Coll, Salvador Guillaumes, Dulce Mombl\u0026aacute;n, and \u0026Oacute;scar Vidal. All authors read and approved the final manuscript.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eKingsnorth A, LeBlanc K (2003) Hernias: inguinal and incisional. Lancet 362:1561\u0026ndash;71. https://doi.org/10.1016/S0140-6736(03)14746-0\u003c/li\u003e\n\u003cli\u003eClaus CMP, Rocha GM, Campos ACL, et al (2016) Prospective, randomized and controlled study of mesh displacement after laparoscopic inguinal repair: fixation versus no fixation of mesh. Surg Endosc 30:1134\u0026ndash;40. https://doi.org/10.1007/s00464-015-4314-7\u003c/li\u003e\n\u003cli\u003eHerniaSurge Group (2018) International guidelines for groin hernia management. Hernia 22:1\u0026ndash;165. https://doi.org/10.1007/s10029-017-1668-x\u003c/li\u003e\n\u003cli\u003eSaia M, Mantoan D, Buja A, et al (2013) Increased rate of day surgery use for inguinal and femoral hernia repair in a decade of hospital admissions in the Veneto Region (north-east Italy): a record linkage study. BMC Health Serv Res 13:349. https://doi.org/10.1186/1472-6963-13-349\u003c/li\u003e\n\u003cli\u003eFarquharson EL (1955) Early ambulation; with special reference to herniorrhaphy as an outpatient procedure. Lancet 269:517\u0026ndash;9. https://doi.org/10.1016/s0140-6736(55)93272-4\u003c/li\u003e\n\u003cli\u003eMitchell JB, Harrow B (1994) Costs and outcomes of inpatient versus outpatient hernia repair. Health Policy 28:143\u0026ndash;52. https://doi.org/10.1016/0168-8510(94)90032-9\u003c/li\u003e\n\u003cli\u003eDeutsch N, Wu CL (2003) Patient outcomes following ambulatory anesthesia. Anesthesiol Clin North Am 21:403\u0026ndash;15. https://doi.org/10.1016/s0889-8537(02)00078-0\u003c/li\u003e\n\u003cli\u003eSinha S, Srinivas G, Montgomery J, DeFriend D (2007) Outcome of day-case inguinal hernia in elderly patients: how safe is it? Hernia 11:253\u0026ndash;6. https://doi.org/10.1007/s10029-007-0220-9\u003c/li\u003e\n\u003cli\u003eSimons MP, Smietanski M, Bonjer HJ, et al (2018) International guidelines for groin hernia management. Hernia 2018 22:1 22:1\u0026ndash;165. https://doi.org/10.1007/S10029-017-1668-X\u003c/li\u003e\n\u003cli\u003eVoorbrood CEH, Burgmans JPJ, Clevers GJ, et al (2015) One-stop endoscopic hernia surgery: efficient and satisfactory. Hernia 19:395\u0026ndash;400. https://doi.org/10.1007/s10029-013-1151-2\u003c/li\u003e\n\u003cli\u003eMillat B, Fingerhut A, Gignoux M, Hay JM (1993) Factors associated with early discharge after inguinal hernia repair in 500 consecutive unselected patients. French Associations for Surgical Research. Br J Surg 80:1158\u0026ndash;60. https://doi.org/10.1002/bjs.1800800932\u003c/li\u003e\n\u003cli\u003eScarfe A, Duncan J, Ma N, et al (2018) Day case hernia repair: weak evidence or practice gap? ANZ J Surg 88:547\u0026ndash;553. https://doi.org/10.1111/ans.14302\u003c/li\u003e\n\u003cli\u003eK\u0026ouml;ckerling F, Lorenz R, Reinpold W, et al (2022) What is the reality in outpatient vs inpatient groin hernia repair? An analysis from the Herniamed Registry. Hernia 26:809\u0026ndash;821. https://doi.org/10.1007/s10029-021-02494-6\u003c/li\u003e\n\u003cli\u003eDrissi F, Jurczak F, Cossa JP, et al (2018) Outpatient groin hernia repair: assessment of 9330 patients from the French \u0026ldquo;Club Hernie\u0026rdquo; database. Hernia 22:427\u0026ndash;435. https://doi.org/10.1007/s10029-017-1689-5\u003c/li\u003e\n\u003cli\u003eKark AE, Belsham PA, Kurzer MN (2005) Simultaneous repair of bilateral groin hernias using local anaesthesia: a review of 199 cases with a five-year follow-up. Hernia 9:131\u0026ndash;3. https://doi.org/10.1007/s10029-004-0304-8\u003c/li\u003e\n\u003cli\u003eAmid PK, Shulman AG, Lichtenstein IL (1996) Simultaneous repair of bilateral inguinal hernias under local anesthesia. 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Curr Opin Anaesthesiol 19:622\u0026ndash;9. https://doi.org/10.1097/ACO.0b013e328010107e\u003c/li\u003e\n\u003cli\u003eWeyhe D, Winnem\u0026ouml;ller C, Hellwig A, et al (2006) [(section sign) 115 b SGB V threatens outpatient treatment for inguinal hernia. Analysis of outcome and economics]. Chirurg 77:844\u0026ndash;55. https://doi.org/10.1007/s00104-006-1208-1\u003c/li\u003e\n\u003cli\u003eDe Lathouwer C, Poullier (2000) How much ambulatory surgery in the World in 1996-1997 and trends? Ambul Surg 8:191\u0026ndash;210. https://doi.org/10.1016/s0966-6532(00)00065-2\u003c/li\u003e\n\u003cli\u003eJarrett PE (2001) Day care surgery. Eur J Anaesthesiol Suppl 23:32\u0026ndash;5\u003c/li\u003e\n\u003cli\u003eKehlet H, Bay-Nielsen M, Danish Hernia Database Collaboration (2008) Nationwide quality improvement of groin hernia repair from the Danish Hernia Database of 87,840 patients from 1998 to 2005. Hernia 12:1\u0026ndash;7. https://doi.org/10.1007/s10029-007-0285-5\u003c/li\u003e\n\u003cli\u003eGuillaumes S, Hidalgo NJ, Bachero I, Juvany M (2023) Outpatient inguinal hernia repair in Spain: a population-based study of 1,163,039 patients-clinical and socioeconomic factors associated with the choice of day surgery. Updates Surg 75:65\u0026ndash;75. https://doi.org/10.1007/s13304-022-01407-1\u003c/li\u003e\n\u003cli\u003eBringman S, Ramel S, Heikkinen T-J, et al (2003) Tension-free inguinal hernia repair: TEP versus mesh-plug versus Lichtenstein: a prospective randomized controlled trial. Ann Surg 237:142\u0026ndash;7. https://doi.org/10.1097/00000658-200301000-00020\u003c/li\u003e\n\u003cli\u003eMetzger J, Lutz N, Laidlaw I (2001) Guidelines for inguinal hernia repair in everyday practice. Ann R Coll Surg Engl 83:209\u0026ndash;14\u003c/li\u003e\n\u003cli\u003ePallati PK, Gupta PK, Bichala S, et al (2013) Short-term outcomes of inguinal hernia repair in octogenarians and nonagenarians. Hernia 17:723\u0026ndash;7. https://doi.org/10.1007/s10029-012-1040-0\u003c/li\u003e\n\u003cli\u003eKurzer M, Kark A, Hussain ST (2009) Day-case inguinal hernia repair in the elderly: a surgical priority. Hernia 13:131\u0026ndash;6. https://doi.org/10.1007/s10029-008-0452-3\u003c/li\u003e\n\u003cli\u003eHajri M, Haddad D, Zaafouri H, et al (2022) Ambulatory hernia repair: a study of 1294 patients in a single institution. Pan Afr Med J 42:235. https://doi.org/10.11604/pamj.2022.42.235.32863\u003c/li\u003e\n\u003cli\u003ePalumbo P, Amatucci C, Perotti B, et al (2014) Outpatient repair for inguinal hernia in elderly patients: still a challenge? Int J Surg 12 Suppl 2:S4\u0026ndash;S7. https://doi.org/10.1016/j.ijsu.2014.08.393\u003c/li\u003e\n\u003cli\u003eCanet J, Raeder J, Rasmussen LS, et al (2003) Cognitive dysfunction after minor surgery in the elderly. Acta Anaesthesiol Scand 47:1204\u0026ndash;10. https://doi.org/10.1046/j.1399-6576.2003.00238.x\u003c/li\u003e\n\u003cli\u003eAmerican Society of Anesthesiologists (2021) ASA Physical Status Classification System. https://www.asahq.org/standards-and-guidelines/asa-physical-status-classification-system. Accessed 12 Mar 2022\u003c/li\u003e\n\u003cli\u003eSanjay P, Jones P, Woodward A (2006) Inguinal hernia repair: are ASA grades 3 and 4 patients suitable for day case hernia repair? Hernia 10:299\u0026ndash;302. https://doi.org/10.1007/s10029-005-0048-0\u003c/li\u003e\n\u003cli\u003eSolodkyy A, Feretis M, Fedotovs A, et al (2018) Elective \u0026ldquo;True Day Case\u0026rdquo; Laparoscopic Inguinal Hernia Repair in a District General Hospital: Lessons Learned from 1000 Consecutive Cases. Minim Invasive Surg 2018:7123754. https://doi.org/10.1155/2018/7123754\u003c/li\u003e\n\u003cli\u003eDrissi F, Gillion JF, Cossa JP, et al (2019) Factors of selection and failure of ambulatory incisional hernia repair: A cohort study of 1429 patients. J Visc Surg 156:85\u0026ndash;90. https://doi.org/10.1016/j.jviscsurg.2018.07.001\u003c/li\u003e\n\u003cli\u003ePalumbo P, Minicucci A, Nasti AG, et al (2007) Treatment for persistent chronic neuralgia after inguinal hernioplasty. Hernia 11:527\u0026ndash;31. https://doi.org/10.1007/s10029-007-0268-6\u003c/li\u003e\n\u003cli\u003ePavlin DJ, Chen C, Penaloza DA, et al (2002) Pain as a factor complicating recovery and discharge after ambulatory surgery. Anesth Analg 95:627\u0026ndash;34, table of contents. https://doi.org/10.1097/00000539-200209000-00025\u003c/li\u003e\n\u003cli\u003eFeliu-Pal\u0026agrave; X, Mart\u0026iacute;n-G\u0026oacute;mez M, Morales-Conde S, Fern\u0026aacute;ndez-Sallent E (2001) The impact of the surgeon\u0026rsquo;s experience on the results of laparoscopic hernia repair. Surg Endosc 15:1467\u0026ndash;70. https://doi.org/10.1007/s00464-001-9017-6\u003c/li\u003e\n\u003cli\u003eSchmedt CG, Sauerland S, Bittner R (2005) Comparison of endoscopic procedures vs Lichtenstein and other open mesh techniques for inguinal hernia repair: a meta-analysis of randomized controlled trials. Surg Endosc 19:188\u0026ndash;99. https://doi.org/10.1007/s00464-004-9126-0\u003c/li\u003e\n\u003cli\u003eFeliu X, Claver\u0026iacute;a R, Besora P, et al (2011) Bilateral inguinal hernia repair: laparoscopic or open approach? Hernia 15:15\u0026ndash;8. https://doi.org/10.1007/s10029-010-0736-2\u003c/li\u003e\n\u003cli\u003eMemon MA, Cooper NJ, Memon B, et al (2003) Meta-analysis of randomized clinical trials comparing open and laparoscopic inguinal hernia repair. Br J Surg 90:1479\u0026ndash;92. https://doi.org/10.1002/bjs.4301\u003c/li\u003e\n\u003cli\u003eRosenberg J, Friis-Andersen H, J\u0026oslash;rgensen LN, Andresen K (2021) Variables in the Danish Hernia Databases: inguinal and ventral. Laparosc Surg 5:30\u0026ndash;30. https://doi.org/10.21037/ls-20-125\u003c/li\u003e\n\u003cli\u003eMadion M, Goldblatt MI, Gould JC, Higgins RM (2021) Ten-year trends in minimally invasive hernia repair: a NSQIP database review. Surg Endosc 35:7200\u0026ndash;7208. https://doi.org/10.1007/s00464-020-08217-9\u003c/li\u003e\n\u003cli\u003ePalser TR, Swift S, Williams RN, et al (2019) Variation in outcomes and use of laparoscopy in elective inguinal hernia repair. BJS Open 3:466\u0026ndash;475. https://doi.org/10.1002/bjs5.50158\u003c/li\u003e\n\u003cli\u003eGuillaumes S, Hoyuela C, Hidalgo NJ, et al (2021) Inguinal hernia repair in Spain. A population-based study of 263,283 patients: factors associated with the choice of laparoscopic approach. Hernia 25:1345\u0026ndash;1354. https://doi.org/10.1007/s10029-021-02402-y\u003c/li\u003e\n\u003cli\u003eAndresen K, Rosenberg J (2021) Decreasing use of open procedures in elective inguinal hernia surgery. Laparosc Surg 5:17\u0026ndash;17. https://doi.org/10.21037/ls-20-126\u003c/li\u003e\n\u003cli\u003eBittner R, Montgomery MA, Arregui E, et al (2015) Update of guidelines on laparoscopic (TAPP) and endoscopic (TEP) treatment of inguinal hernia (International Endohernia Society). Surg Endosc 29:289\u0026ndash;321. https://doi.org/10.1007/s00464-014-3917-8\u003c/li\u003e\n\u003cli\u003ePoelman MM, van den Heuvel B, Deelder JD, et al (2013) EAES Consensus Development Conference on endoscopic repair of groin hernias. Surg Endosc 27:3505\u0026ndash;19. https://doi.org/10.1007/s00464-013-3001-9\u003c/li\u003e\n\u003cli\u003eSimons MP, Aufenacker T, Bay-Nielsen M, et al (2009) European Hernia Society guidelines on the treatment of inguinal hernia in adult patients. Hernia 13:343\u0026ndash;403. https://doi.org/10.1007/s10029-009-0529-7\u003c/li\u003e\n\u003cli\u003eBittner R, Arregui ME, Bisgaard T, et al (2011) Guidelines for laparoscopic (TAPP) and endoscopic (TEP) treatment of inguinal hernia [International Endohernia Society (IEHS)]. Surg Endosc 25:2773\u0026ndash;843. https://doi.org/10.1007/s00464-011-1799-6\u003c/li\u003e\n\u003cli\u003eHidalgo NJ, Guillaumes S, Bachero I, et al (2023) Trends and predictors of laparoscopic bilateral inguinal hernia repair in Spain: a population-based study. Surg Endosc 37:4784\u0026ndash;4794. https://doi.org/10.1007/s00464-023-09967-y\u003c/li\u003e\n\u003cli\u003eTrevisonno M, Kaneva P, Watanabe Y, et al (2015) A survey of general surgeons regarding laparoscopic inguinal hernia repair: practice patterns, barriers, and educational needs. Hernia 19:719\u0026ndash;24. https://doi.org/10.1007/s10029-014-1287-8\u003c/li\u003e\n\u003cli\u003eWhippey A, Kostandoff G, Paul J, et al (2013) Predictors of unanticipated admission following ambulatory surgery: a retrospective case-control study. Can J Anaesth 60:675\u0026ndash;83. https://doi.org/10.1007/s12630-013-9935-5\u003c/li\u003e\n\u003cli\u003eKingsnorth AN, Bowley DMG, Porter C (2003) A prospective study of 1000 hernias: results of the Plymouth Hernia Service. Ann R Coll Surg Engl 85:18\u0026ndash;22. https://doi.org/10.1308/003588403321001363\u003c/li\u003e\n\u003cli\u003eVan Caelenberg E, De Regge M, Eeckloo K, Coppens M (2019) Analysis of failed discharge after ambulatory surgery: unanticipated admission. Acta Chir Belg 119:139\u0026ndash;145. https://doi.org/10.1080/00015458.2018.1477488\u003c/li\u003e\n\u003cli\u003eNgo P, P\u0026eacute;lissier E, Levard H, et al (2010) Ambulatory groin and ventral hernia repair. J Visc Surg 147:e325-8. https://doi.org/10.1016/j.jviscsurg.2010.09.003\u003c/li\u003e\n\u003cli\u003eHidalgo NJ, Bachero I, Hoyuela C, et al (2022) The transition from open to laparoscopic surgery for bilateral inguinal hernia repair: how we did it. Langenbecks Arch Surg 407:3701\u0026ndash;3710. https://doi.org/10.1007/s00423-022-02671-w\u003c/li\u003e\n\u003cli\u003eGuillaumes S, Juvany M (2022) Inguinal hernia repairs performed for recurrence in Spain: population-based study of 16 years and 1,302,788 patients. Hernia 26:1023\u0026ndash;1032. https://doi.org/10.1007/s10029-022-02630-w\u003c/li\u003e\n\u003cli\u003eTrevisonno M, Kaneva P, Watanabe Y, et al (2015) Current practices of laparoscopic inguinal hernia repair: a population-based analysis. Hernia 19:725\u0026ndash;33. https://doi.org/10.1007/s10029-015-1358-5\u003c/li\u003e\n\u003cli\u003eMuaddi H, Stukel TA, de Mestral C, et al (2023) The evolving use of robotic surgery: a population-based analysis. Surg Endosc 37:1870\u0026ndash;1877. https://doi.org/10.1007/s00464-022-09643-7\u003c/li\u003e\n\u003cli\u003eSmith FJ, Holman CDJ, Moorin RE, Fletcher DR (2008) Incidence of bariatric surgery and postoperative outcomes: a population-based analysis in Western Australia. Med J Aust 189:198\u0026ndash;202. https://doi.org/10.5694/j.1326-5377.2008.tb01981.x\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"langenbecks-archives-of-surgery","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"laos","sideBox":"Learn more about [Langenbeck's Archives of Surgery](http://link.springer.com/journal/423)","snPcode":"423","submissionUrl":"https://submission.nature.com/new-submission/423/3","title":"Langenbeck's Archives of Surgery","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"bilateral inguinal hernia, outpatient surgery, unplanned overnight admission, laparoscopic surgery","lastPublishedDoi":"10.21203/rs.3.rs-3576250/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-3576250/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003ePurpose\u003c/h2\u003e \u003cp\u003eThe use of outpatient surgery in inguinal hernia is heterogeneous despite clinical recommendations. This study aimed to analyze the utilization trend of outpatient surgery for bilateral inguinal hernia repair (BHIR) in Spain and identify the factors associated with outpatient surgery choice and unplanned overnight admission.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eA retrospective observational study of patients undergoing BIHR from 2016 to 2021 was conducted. The clinical-administrative database of the Spanish Ministry of Health RAE-CMBD was used. Patient characteristics undergoing outpatient and inpatient surgery were compared. A multivariable logistic regression analysis was performed to identify factors associated with outpatient surgery choice and unplanned overnight admission.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eA total of 30,940 RHIBs were performed; 63% were inpatient surgery, and 37% were outpatient surgery. The rate of outpatient surgery increased from 30% in 2016 to 41% in 2021 (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Higher rates of outpatient surgery were observed across hospitals with a higher number of cases per year (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Factors associated with outpatient surgery choice were: age under 65 years (OR: 2.01, 95% CI: 1.92\u0026ndash;2.11), hospital volume (OR: 1.59, 95% CI: 1.47\u0026ndash;1.72), primary hernia (OR: 1.89, 95% CI: 1.71\u0026ndash;2.08), and laparoscopic surgery (OR: 1.47, 95% CI: 1.39\u0026ndash;1.56). Comorbidities were negatively associated with outpatient surgery. Open surgery was associated (OR: 1.26, 95% CI: 1.09\u0026ndash;1.47) with unplanned overnight admission.\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eOutpatient surgery for BHIR has increased in recent years but is still low. Older age and comorbidities were associated with lower rates of outpatient surgery. However, the laparoscopic repair was associated with increased outpatient surgery and lower unplanned overnight admission.\u003c/p\u003e","manuscriptTitle":"Outpatient surgery and unplanned overnight admission in bilateral inguinal hernia repair: a population-based study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-04-19 19:11:15","doi":"10.21203/rs.3.rs-3576250/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"editorInvitedReview","content":"","date":"2023-12-21T21:48:38+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"61095209-9971-4a53-b068-4d00164375f3","date":"2023-12-13T08:50:29+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"03ae0a2b-0a6d-495f-9cf3-56606e632092","date":"2023-12-11T08:10:48+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2023-12-11T07:44:28+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2023-11-21T22:01:20+00:00","index":"","fulltext":""},{"type":"submitted","content":"Langenbeck's Archives of Surgery","date":"2023-11-21T19:53:14+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"langenbecks-archives-of-surgery","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"laos","sideBox":"Learn more about [Langenbeck's Archives of Surgery](http://link.springer.com/journal/423)","snPcode":"423","submissionUrl":"https://submission.nature.com/new-submission/423/3","title":"Langenbeck's Archives of Surgery","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"ad8897eb-9459-47e4-bab4-68b7b17fbbdf","owner":[],"postedDate":"April 19th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2024-05-22T04:14:21+00:00","versionOfRecord":[],"versionCreatedAt":"2024-04-19 19:11:15","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-3576250","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-3576250","identity":"rs-3576250","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}