Relationship between Intrinsic Capacity, Physical Resilience and Frailty among elderly patients during stroke recovery: A cross-lagged panel study

Relationship between Intrinsic Capacity, Physical Resilience and Frailty among elderly patients during stroke recovery: A cross-lagged panel study | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Relationship between Intrinsic Capacity, Physical Resilience and Frailty among elderly patients during stroke recovery: A cross-lagged panel study Yanfang Zhang, Xiaomei Ji, Yuanyuan Yu, Manman Hu, Liangliang Sun, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8446143/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 13 You are reading this latest preprint version Abstract Background The existing designs are difficult to reveal the causal temporal relationship and dynamic interaction mechanism among intrinsic capacity(IC), physical resilience(PR), and frailty. Objective This study aims to investigate the longitudinal relationships between IC, PR, and frailty in elderly stroke patients during the rehabilitation phase, and to reveal their potential mediating roles. Methods From November 2024 to November 2025, this study employed convenience sampling to select stroke patients admitted to the neurology departments of four Grade A tertiary general hospitals in Anhui Province as research subjects. The IC questionnaire, The Physical Resilience Instrument for Older Adults (PRIFOR), and The FRAIL Scale were used as measurement tools, with observations conducted at three time points: discharge (T1),3 months post-discharge (T2), and 6 months post-discharge (T3). The cross-lag model was used to analyze the causal relationships among IC, PR, and frailty in elderly stroke patients during stroke recovery. Results the FRAIL scores were negatively correlated with PR scores( r =-0.1,00~-0.628) and IC scores( r =-0.136~-0.427), while PR scores were positively correlated with IC scores( r =0.146~0.644).Cross-lagged analysis showed (Figure 1) that IC scores and FRAIL scores had bidirectional predictive effects ( β =-0.055 to-0.298, both P <0.05).Longitudinal mediating effect analysis showed that indirect effect of T2 PR scores between T1 IC scores and T3 FRAIL scores was -0.078 (95%CI=-0.168～-0.074), the direct effect was -0.246 (95%CI=-0.481～-0.252), the total effect was -0.324 (95% CI = -0.583～-0.374), and the mediating effect accounted for 24.07%. Conclusions The lower the level of IC, the higher the degree of frailty in the elderly patients with post-stroke recovery, and the PR plays a mediating role between the two. Elder Stroke Intrinsic Capacity Physical Resilience Frailty Cross-Lagged Panel Study Figures Figure 1 Figure 2 Background Data from the Global Burden of Disease Study (GBD) has demonstrated that stroke has become the second leading cause of death and the third leading cause of disability worldwide [1] , as well as the primary cause of mortality and disability among adults in China [2] . The incidence of stroke shows a significant age-related increasing trend [3] , with a mean age of onset of 65 years; in individuals aged 40 years and above, the age of first stroke onset is concentrated between 60.9 and 63.4 years [2] , indicating that the elderly population is the core affected group of stroke. Stroke is characterized by high incidence, high complication rate, high disability rate, high recurrence rate, and high mortality [4] . It not only results in multidimensional functional impairments in patients, including motor, sensory, balance, coordination, and cognitive dysfunctions [1] , but also imposes an overwhelming socioeconomic burden [5] , thereby posing a severe threat to the health and well-being of the elderly population. Frailty is a clinical syndrome occurring in older adults, resulting from the degenerative changes in the physiological functions of multiple systems including the neurological, muscular, endocrine, and immune systems [6] . It is characterized by reduced physiological reserve and diminished capacity to cope with stressors [6] . The prevalence of frailty among stroke patients ranges from 23.8% to 54.6% [7] . Moreover, stroke patients with comorbid frailty are more likely to experience adverse outcomes, such as prolonged hospital stays, physical function deterioration, and elevated 90-day post-stroke mortality [8] , which severely impair the rehabilitation progress and prognostic quality. The comprehensive frailty model proposed by Gobbens et al. [9] suggests that frailty is a dynamically evolving process throughout the life course, regulated by multiple factors including age, educational level, and lifestyle, and involves physical, somatic, and social dimensions. Rehabilitation intervention is a crucial component in improving the prognosis of stroke patients [10] . Studies have confirmed that scientific and effective rehabilitation training during the recovery period can significantly slow down the progression of functional disability and accelerate the rehabilitation process in stroke patients [11] . Therefore, rehabilitation treatment in the recovery period holds equal clinical significance to acute-phase treatment and preventive intervention. It plays a positive role in maintaining patients’ healthy living conditions and reducing the disease burden. However, current studies on frailty in older stroke patients are mostly confined to cross-sectional correlation analyses or single-time-point prognostic predictions, lacking in-depth exploration of its dynamic evolutionary process and underlying mechanisms. Such limitations make it difficult to meet the demands of rehabilitation intervention and precise management during the recovery period. Intrinsic Capacity (IC) refers to the comprehensive manifestation of an individual’s physical and mental functions at any stage, and serves as the core carrier for achieving healthy aging [12-14] . Its core dimensions include five modules: motor function, cognition, vitality, perception, and psychology [12-14] . This concept has been incorporated by the World Health Organization (WHO) into the Guidelines for Integrated Care for Older People and the ICOPE Workbook, becoming a core target for elderly health management [13] . Existing studies have confirmed that the decline of IC in older adults is closely associated with various adverse health outcomes [15-17] . The detection rate of IC decline in older stroke patients during the recovery period has reached 45.34% [18] , which not only leads to the deterioration of patients’ physical functions, worsening of clinical indicators, and excessive consumption of medical resources [19] , but also becomes a key bottleneck hindering the achievement of healthy aging. Maintaining and optimizing the IC of patients during the recovery period is an important approach for formulating personalized rehabilitation plans, improving the quality of life in old age, and reducing adverse outcomes [20] . There is partial overlap and complementarity in the conceptual connotations between IC and frailty [21] . Compared with the negative orientation of frailty that focuses on health deficits, IC emphasizes an individual’s existing functional potential and possesses positive health attributes [21] . Frailty is not the decline of a single organ system, but the result of the interaction between environmental factors and individual physiological reserve [22] . When the IC declines to a critical vulnerability threshold, the body cannot maintain homeostasis in the face of minor endogenous or exogenous stressors, ultimately inducing frailty [22] . Studies have suggested that the decline of IC can more accurately reflect the frailty characteristics of older adults, and dynamic tracking of changes in IC during the frailty trajectory can uncover more abundant prognostic information [23] ; however, other studies have shown that IC decline is more likely to occur in the context of frailty [24, 25] . Therefore, it is difficult to clarify whether low IC induces or exacerbates frailty, or whether the frailty state inhibits the improvement of IC. Moreover, there is a lack of exploration on the dynamic correlation mechanism between the two at the current stage, ignoring the state fluctuations and mutual influences of individuals at different rehabilitation stages. Based on this, this study adopts a longitudinal follow-up design to analyze the bidirectional predictive relationship between the two and clarify the causal chain, which has important theoretical and practical value for accurately identifying high-risk groups of frailty and formulating early intervention strategies centered on improving IC. Physical Resilience (PR) refers to an individual’s ability to achieve functional recovery or optimization when confronting age-related injuries or diseases [26] . It can effectively predict the long-term health status and lifespan of older adults, and serves as a key entry point for promoting successful aging [27] . Monitoring of functional change trajectories is regarded as the "gold standard" for the quantitative assessment of PR [28] . Kolk et al. [29] constructed trajectories of PR changes by retrospectively evaluating the Activities of Daily Living (ADL) of older adults hospitalized due to acute diseases at 2 weeks before admission and 3 months after admission. However, this method relies on historical stressor trajectory data, and the lack of real-time monitoring limits the reliability of the results [28] . Clinically, frailty is often considered an external manifestation of low PR [30] . Although there is an association between the two, there are essential differences in their conceptual nature: PR runs through the entire life course, while frailty mainly occurs in old age [30] ; PR focuses on the accumulation of positive health attributes, whereas frailty is characterized by health deficits and functional limitations [31] . Therefore, PR is recognized as an early and sensitive indicator for predicting healthy aging [32] . Existing studies have confirmed the correlation between PR and frailty [33] , but the causal temporal relationship between them remains unclear. It is urgent to break through the limitations of static analysis, reveal the dynamic interaction rules of the two in the time dimension, and provide evidence-based basis for early frailty screening and functional preservation interventions. There is a close association between PR and IC. Both characterize the body’s reserve capacity, emphasize the positive health attributes of older adults, and are regulated by external environmental factors, yet they cannot be equated. Some scholars have proposed that IC can serve as a high-level comprehensive indicator of physiological reserve, and its impact on PR may be achieved through a mediating effect [34] . Wu et al. [35] confirmed that individuals with high PR often possess good IC, which can effectively adapt to and mitigate cumulative systemic damage. Chhetri et al. [36] further pointed out that IC is a core determinant of PR. However, a study suggested that a high level of IC does not necessarily equate to strong PR, indicating a complex dynamic association between the two [37] . Their quantitative relationship and mechanism of action still require in-depth exploration. In summary, IC, PR, and frailty all focus on aging-related reserve capacity, and there exists a potential dynamic interactive relationship among the three [38] . Whitson et al. [28] first constructed a structural model of PR in 2016. On this basis, Chhetri et al. [36] and Li et al. [39] optimized the model by integrating the association between IC and frailty, clarifying a pathway framework that takes PR as the link and integrates pre-existing influencing factors, exposure to health stressors, and aging outcomes. Although existing studies have initially confirmed the correlation among the three, there are significant limitations: first, the research objects are mostly the general elderly population, with few focusing on the special group of older adults in the recovery period of stroke; second, the existing designs are difficult to reveal the causal temporal relationship and dynamic interaction mechanism among the three. Based on the pathophysiological characteristics of older adults in the recovery period of stroke, this study adopts a cross-lagged model to systematically explore the dynamic causal relationship and temporal action pathway among IC, PR, and frailty. The conduct of this study, on the one hand, can fill the gap in longitudinal mechanism research on the three in older adults during the stroke recovery period and enrich the theoretical system related to aging reserve capacity; on the other hand, it can accurately locate intervention targets and temporal nodes, provide empirical support for formulating frailty screening programs and phased intervention strategies that are consistent with the rehabilitation process, and have important public health value for improving the health prognosis of older adults in the stroke recovery period and reducing the medical burden. Materials and methods Study design and participants In the sample size calculation of this study, the measured data obtained from the pilot study were used as the basis for effect size estimation [40] . A total of 300 subjects were included in the pilot study, and cross-sectional measurements were conducted using the IC Questionnaire and the FRAIL Scale. The results showed a negative correlation between IC score and FRAIL score (r=-0.084, P<0.001). Based on this, the correlation coefficient was converted into an effect size according to the formula f²=r²/(1-r²) [41] . Subsequently, G*Power 3.1 software [42] was used to calculate the sample size based on the repeated measures analysis of variance (ANOVA) model. The parameters were set as follows: 3 repeated measurements, estimated effect size f=0.08, significance level α=0.05, and test power (1-β)=0.95. The calculated basic sample size was 404. Considering a further 10% invalid questionnaires, the minimum sample size required for this study was finally determined to be 450. From November 2024 to November 2025, convenience sampling was used to select stroke patients admitted to the Department of Neurology of 4 Grade A tertiary general hospitals in Anhui Province as the research subjects. Inclusion criteria: (1) Meeting the diagnostic criteria for stroke and confirmed by cranial CT or MRI; (2) Aged > 60 years; (3) In the stroke recovery period, with clear consciousness and stable condition; (4) Capable of effective verbal and written communication; (5) Voluntarily participating after being informed of the study and signing the informed consent form. Exclusion criteria: (1) Severe hearing or language expression disorders; (2) Patients with severe heart, liver, kidney function impairment or advanced malignant tumors. This research adhered to the guidelines of the Declaration of Helsinki and received approval from the Ethics Committee of Bengbu Medical University (Approval No. 2025-184). All participants provided written informed consent. In accordance with relevant guidelines [43] , data were collected at three time points in this study: at discharge (T1), 3 months after discharge (T2), and 6 months after discharge (T3). The research team consisted of 2 neurosurgical nurses who had received unified training and passed the assessment. Prior to the survey, informed consent was obtained from the respondents, and the purpose of the survey and the principle of confidentiality were explained to each respondent using unified guidelines. The initial survey at T1 was conducted through on-site questionnaires to ensure that the investigators could clearly fill in the relevant instructions on precautions. Follow-up surveys at T2 and T3 after discharge were carried out through telephone, WeChat, hospital outpatient visits, home visits, and other methods, and the appropriate follow-up location and time were arranged according to the actual situation of the patients. All data were double-checked and entered according to unified standards. If there were doubts about the answers or missing responses, the researchers themselves confirmed with the respondents by telephone or other means. If any respondent withdrew midway during the survey, the survey data were treated as invalid. A total of 450 elderly stroke patients were surveyed in this study. At T1, 450 valid questionnaires were recovered. During the T2 follow-up, 8 cases were lost to follow-up (2 cases lost contact, 3 cases died, 3 cases refused). During the T3 follow-up, 11 cases were lost to follow-up (3 cases lost contact, 1 case died, 4 cases refused, 3 cases with extremely poor physical condition). A total of 19 cases were lost to follow-up, and finally, data from 431 cases were valid, with an effective recovery rate of 95.78%. Methods Intrinsic Capacity (IC) In 2019, the World Health Organization (WHO) developed a screening tool consisting of 5 dimensions and 9 indicators to assess the decline in intrinsic capacity [44] . The dimensions and indicators are defined as follows:（1）Locomotion: Impaired locomotion is identified by failure in the 5-time chair stand test, i.e., inability to complete 5 repetitions of standing up and sitting down within 14 seconds.（2）Vitality: It refers to unintended weight loss of more than 3 kg within the past 90 days or loss of appetite.（3）Sensory: This dimension encompasses vision and hearing, focusing on whether poor eyesight or hearing impairs daily living activities.（4）Cognition: Cognitive decline is determined by incorrect responses to time or orientation questions, or failure to recall 3 words as required.（5）Psychological: Depression is defined as experiencing low mood, hopelessness, or loss of interest in all activities over the past 14 days.Each item is scored on a binary scale: a "Yes" response is assigned 0 point, while a "No" response is assigned 1 point. The total score ranges from 0 to 5, with higher scores indicating higher levels of intrinsic capacity. The ICOPE screening tool has been validated by domestic scholars and demonstrated good applicability in the Chinese population [13] . The Physical Resilience Instrument for Older Adults (PRIFOR) The scale was developed by Hu et al. [45] , which is used to assess the PR of older adults under acute stressors. Li Jiaxin et al. [46] translated it into a simplified Chinese version, including 3 dimensions: Positive Thinking (4 items), Coping and Adjusting Lifestyle (7 items), and Belief and Hope Attitude (5 items). A 5-point Likert scale was used, with scores ranging from 1 to 5 from "Strongly Disagree" to "Strongly Agree". Higher scores indicate higher levels of PR. The reliability and validity of the scale in this study were verified. The FRAIL Scale The scalewas proposed by experts from the International Working Group on Nutrition, Health and Aging [47] . It is a 5-item scale, with 1 point assigned for "Yes" and 0 point for "No" for each item. The total score ranges from 0 to 5: 1-2 points indicate pre-frailty, and 3 points or more indicate frailty. Statistical analysis SPSS 25.0 software was used for descriptive statistics and Pearson correlation analysis of the scores of the IC, PR, and FRAIL measured at three time points. Mplus 8.3 software was employed to test the longitudinal measurement invariance of the IC , PR, and FRAIL, and a cross-lagged model was constructed to examine the relationships among IC, PR, and Frailty. The bootstrap method with 2000 repeated samplings was used to test the longitudinal mediating effect of PR between IC and Frailty. The Harman's single-factor test was applied to conduct factor analysis on all items of variables at T1, T2, and T3 respectively. The results showed that three factors with eigenvalues greater than 1 were extracted at all three time points, and the explanatory rates of the largest common factor were 21.25%, 20.71%, and 22.45% respectively, indicating that there was no obvious common method bias in this study. Results Characteristics of the participants A total of 431 elderly patients with stroke in the recovery stage were recruited, with an age range of 60–85 years and a mean age of 70.33 ± 5.119 years. Among them, there were 325 males and 106 females; 281 were from rural areas, 96 from towns and 54 from cities; 405 were married, 16 divorced, 7 widowed and 3 unmarried; 95 had an educational level of primary school or below, 292 had middle school education and 44 had college education or above; 319 lived with spouses, 40 lived alone, 54 lived with children and 18 had other living arrangements; in terms of monthly per capita household income, 35 cases were ≤ 1500 yuan, 207 cases were in the range of 1501–3000 yuan, 162 cases were 3001–4500 yuan and 27 cases were > 4500 yuan; regarding stroke type, 184 cases were ischemic stroke, 171 cases were intracerebral hemorrhage and 76 cases were subarachnoid hemorrhage; 115 patients had a fall history in the past year while 316 did not; 132 received regular rehabilitation treatment or exercise and 299 did not; 301 had a history of smoking and drinking and 130 did not; in terms of the number of comorbid chronic diseases, 26 cases had more than 3 chronic diseases, 330 cases had 1–3 chronic diseases and 75 cases had no chronic diseases. Descriptive Statistics and Correlation Analysis of Variables The correlation analysis results demonstrated that, except for the T1P and T3IC correlation coefficients which were not statistically significant, the pairwise correlations of IC, PR, and decay scores at all three time points were statistically significant. Among them, the FRAIL scores were negatively correlated with PR scores( r =-0.1,00~-0.628) and IC scores( r =-0.136~-0.427), while PR scores were positively correlated with IC scores( r =0.146~0.644) (Table 1). Longitudinal Measurement Invariance Configural Invariance, Metric Invariance, and Scalar Invariance models were established respectively for the item scores of the IC, PR, and FRAIL at the three time points. The results are shown in Table 2. All models exhibited good fit (CFI > 0.90, TLI > 0.90, RMSEA < 0.08), and the changes in fit indices of the nested models were all less than 0.01, indicating that the research instruments met the assumption of longitudinal measurement invariance. Cross-Lagged Analysis Age was included as a control variable to construct a cross-lagged model of IC item scores and FRAIL scores. All fit indices of the model met psychometric requirements (χ²=104, df =18, χ²/df =5.778, CFI = 0.922, TLI = 0.900, RMSEA=0.046). Cross-lagged analysis showed (Figure 1) that IC scores and FRAIL scores had bidirectional predictive effects ( β =-0.055 to-0.298, both P <0.05). Figure 1 Cross-lagged Model of Intrinsic Capacity and Frailty in Older Adults with Stroke in Recovery Period Longitudinal mediating effect analysis Age was included as a control variable to construct a cross-lagged model of IC scores, PR scores, and FRAIL scores. All fit indices of the model met psychometric requirements (χ²=102.244, df =12, χ²/df =8.520, CFI = 0.922, TLI = 0.904, RMSEA=0.052). Specifically, T1 IC scores positively predicted T2 PR and T3 FRAIL scores ; T1 PR scores negatively predicted T2 FRAIL scores, positively predicted T2 IC scores; T1 FRAIL scores negatively predicted T2 PR scores and positively predicted T2 FRAIL scores; T2 IC scores positively predicted T3 PR scores; T2 PR scores negatively predicted T3 FRAIL scores ; T2 FRAIL scores negatively predicted T3 PR scores(Figure 2). Furthermore, the bootstrap method was used to test the longitudinal mediating effect of PR between IC and Frailty, with age as the control variable. The results showed that the indirect effect of T2 PR scores between T1 IC scores and T3 FRAIL scores was -0.078 (95%CI=-0.168～-0.074), the direct effect was -0.246 (95%CI=-0.481～-0.252), the total effect was -0.324 (95% CI = -0.583～-0.374), and the mediating effect accounted for 24.07%. Figure 2 Cross-lagged Mediation Model of IC, PR and Frailty in Older Adults with Stroke in Recovery Period Discussion This study conducted three follow-up surveys over 6 months on IC, PR, and Frailty in older adults with stroke in the recovery period, aiming to explore the bidirectional relationship between IC and Frailty as well as the longitudinal mediating role of PR between them. The results of correlation analysis showed that the correlations of IC, PR, and Frailty were significant both at the same time point and across different time points, which was consistent with previous studies [38, 48] , indicating an inherent association among the three. The results of the cross-lagged analysis in this study indicated that the intrinsic capacity of elderly patients during the recovery period of stroke exerts a significant negative predictive effect on frailty. This is consistent with previous studies, as the decline in intrinsic capacity is a robust indicator for predicting the occurrence and progression of frailty in the elderly [49] . When one or more dimensions of intrinsic capacity are impaired, an individual's ability to cope with daily challenges and sudden health events is weakened, thereby increasing the risk of frailty [50] . For instance, the decline in motor function (e.g., decreased grip strength, slowed gait speed) is a core manifestation of frailty and also a crucial marker of impaired intrinsic capacity [50] . In addition, cognitive impairment (e.g., memory loss, inattention) can affect the elderly's self-management abilities and social participation, further exacerbating the progression of frailty [51] . When a stroke occurs, elderly individuals with higher intrinsic capacity can better mobilize their "functional capital" [52] —for example, performing rehabilitation training through strong muscle strength, understanding and executing rehabilitation instructions by virtue of good cognitive function, and coping with the challenges brought by the disease with a positive psychological state [53] . When the reserve of intrinsic capacity is sufficient, even in the face of stressors such as illness or injury, the elderly can better maintain physiological homeostasis and achieve functional reconstruction, thereby delaying or avoiding the occurrence of frailty [54] . This study also found that frailty in elderly patients during the recovery period of stroke also has a significant negative predictive effect on intrinsic capacity. This indicates that there is a complex bidirectional relationship between the two, which is consistent with previous studies [55] . Frailty forms a self-reinforcing loop through multiple dimensional pathways such as inflammation, psychological depression, and activity restriction, leading to the continuous decline of IC [24] . Frailty is characterized by the exhaustion of physiological reserve and multisystem dysfunction, which directly results in a further decline in intrinsic capacity [24] . Multiple factors such as physical activity, bone mineral density, bone diseases, heart rate, blood pressure, oxidative stress, smoking, lifestyle, nutrition, self-efficacy, and depression are associated with aging and physical activity, among which sarcopenia is a disease closely related to frailty and healthy muscle aging [56] . In addition, frailty may indirectly impair the psychological and social dimensions of intrinsic capacity by affecting mood, cognition, and social participation [57] . This negative impact may lead to reduced activity and social isolation in the elderly, ultimately accelerating the comprehensive degradation of intrinsic capacity [58] . This finding challenges the traditional linear view that regards frailty as a result of IC decline, suggesting that clinical interventions need to simultaneously focus on the synergistic improvement of both. Further longitudinal mediation analysis results showed that T2 PR played a mediating role in the predictive pathway of T1 IC on T3 Frailty. This pathway reveals a "protective mechanism": a higher initial level of IC provides the body with a kind of "redundancy", enabling it to mobilize more resources for repair when facing environmental stress, thereby delaying the occurrence of Frailty [44] . In addition, it verifies the progressive protective logic of "neuroregulation - physical adaptation - functional maintenance" at the neural mechanism level. IC provides the foundation for PR by maintaining brain region functional connectivity, neurotransmitter balance, and neuroendocrine stability [59] . PR serves as an intermediate carrier for IC to exert its protective effect [36] . PR is a positive physiological adaptation process; by enhancing neuroplasticity, it helps individuals reorganize neural networks when facing chronic stress, preventing toxic damage caused by excessive activation of the HPA axis [60] . Effective Resilience acts as a Buffer, blocking the destructive effects of long-term stress hormones (such as cortisol) on the cognitive and immune systems, thereby delaying the pathological progression of Frailty [61] .This finding provides precise intervention targets for the Frailty in the elderly, and has both theoretical expansion and clinical practice value. Strengths and limitations of this study This study adopted a three-phase longitudinal follow-up design and focused on the special population of older adults in the recovery period of stroke, clarifying the bidirectional predictive and mediating relationships among IC, PR and frailty. This finding makes up for the limitation of previous studies that only focused on the direct association between the two, and deepens the understanding of the dynamic correlation between physiological decline and IC in the elderly.By applying cross-lagged and mediation models, it reveals the temporal effect pathways among variables and provides a theoretical basis for precise intervention. Age was strictly controlled as a confounding variable to ensure the reliability of the results, and the findings possess both theoretical expansion and clinical practical value. This study has the following limitations: First, the exploration of moderating variables in the bidirectional pathways is insufficient. Except for age, the impacts of potential moderating factors such as gender, social support, and lifestyle on the strength of relationships among variables remain unclear. In the future, multi-center, large-sample, and cross-regional longitudinal studies are needed to include groups with different demographic characteristics and social backgrounds, and add moderating variable analysis to clarify group differences, thereby providing a basis for precise interventions. Second, the mechanism verification lacks direct objective evidence. The current mechanism analysis is mostly derived based on existing studies, and objective detection data such as neuroimaging and neurobiochemistry of the study samples are not included, making it difficult to accurately quantify the mechanism associations. In subsequent studies, relevant detection technologies should be combined to further verify the core targets of neural mechanisms and consolidate the theoretical foundation. Third, the sample representativeness is limited, and the generalizability of the conclusions needs to be further verified by multi-center, large-sample, and cross-regional cohort studies. Fourth, the revelation of dynamic associations is insufficient. The study only conducts analysis through 3 time points, which is difficult to reflect the dynamic fluctuations and interactive effects of IC, PR, and Frailty. In the future, it is necessary to extend the research cycle, increase the number of time points, explore the dynamic change rules of variables, and refine the temporal characteristics of bidirectional effects. Conclusion Through a 3-phase longitudinal follow-up design, this study found a bidirectional predictive relationship between IC and Frailty, and simultaneously revealed that PR plays a mediating role between them. This finding not only enriches the theoretical system of "Capacity-Resilience-Frailty" in the field of geriatric health but also provides a new basis for the clinical formulation of targeted intervention strategies. Declarations Acknowledgements The authors would like to thank all patients for their voluntarily participating and the staff for their help with data collection in this study. Author Contributions Yanfang Zhang : Conceptualization, data curation, formal analysis, investigation, writing original draft, and writing review editing. Xiaomei Jia, Yuanyuan Yub, Manman Huc, Liangliang Sund, Lihua Wange,Long Zhao : Data curation. investigation, methodology, and writing review and editing. Xiumu Yang :funding acquisition, methodology, project administration, supervision. Funding The author(s) declare that financial support was received for the research and/or publication of this article. This work was supported by University Scientific Research Project of Bengbu Medical University ( 2024byzd163sk; 2023byfy142sk ;2022byzd130sk), Longhu Talent Project of Bengbu Medical University( LH250201001 ), Key project of humanities and social sciences of Anhui Provincial Department of Education( 2024AH040341;2023AH051903 ). Data Availability Statement The anonymized data that support the findings of this study were available from the author (Yangfang Zhang) upon reasonable request. The data were not publicly available due to privacy and ethical restriction. Ethics approval and consent to participate This research adhered to the guidelines of the Declaration of Helsinki and received approval from the Ethics Committee of Bengbu Medical University (Approval No. 2025-184). All participants provided written informed consent. Consent for publication None. Conflict Of Interest Statement There were no financial disclosures or conflicts of interest to disclose. 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Supplementary Files Table1and2.doc Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 10 Mar, 2026 Reviews received at journal 16 Feb, 2026 Reviews received at journal 15 Feb, 2026 Reviewers agreed at journal 13 Feb, 2026 Reviewers agreed at journal 07 Feb, 2026 Reviewers agreed at journal 06 Feb, 2026 Reviews received at journal 05 Feb, 2026 Reviewers agreed at journal 05 Feb, 2026 Reviewers invited by journal 05 Feb, 2026 Editor assigned by journal 03 Feb, 2026 Editor invited by journal 14 Jan, 2026 Submission checks completed at journal 14 Jan, 2026 First submitted to journal 14 Jan, 2026 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. 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IC: Intrinsic Capacity, F: Frailty; T1:at discharge,T2:3 months after discharge,T3:6 months after discharge;Age was included as a control variable.Non-significant paths are not labeled in the figure.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-8446143/v1/e77b01f9c585c174650abfb1.png"},{"id":102214924,"identity":"a6de2399-b24c-488e-bf9c-bb2318d76d08","added_by":"auto","created_at":"2026-02-09 12:47:47","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":196367,"visible":true,"origin":"","legend":"\u003cp\u003eCross-lagged Mediation Model of IC, PRand Frailty in Older Adults with Stroke in Recovery Period\u003c/p\u003e\n\u003cp\u003eNote. IC: Intrinsic Capacity, P: Physical Resilience, F: Frailty; T1:at discharge,T2:3 months after discharge,T3:6 months after discharge;age was included as a control variable.Non-significant paths are not labeled in the figure.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-8446143/v1/007f4880e8a5104723d08de8.png"},{"id":102301816,"identity":"6432970a-320a-4b3b-ba79-438670780dda","added_by":"auto","created_at":"2026-02-10 11:23:32","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1086077,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8446143/v1/b95072be-812a-4bbf-80be-8586940607c5.pdf"},{"id":102297365,"identity":"798c2322-9e87-4fb5-8b94-451c18e844ba","added_by":"auto","created_at":"2026-02-10 10:27:13","extension":"doc","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":36352,"visible":true,"origin":"","legend":"","description":"","filename":"Table1and2.doc","url":"https://assets-eu.researchsquare.com/files/rs-8446143/v1/b214a7ce97ea4a44bf5b6cc6.doc"}],"financialInterests":"No competing interests reported.","formattedTitle":"Relationship between Intrinsic Capacity, Physical Resilience and Frailty among elderly patients during stroke recovery: A cross-lagged panel study","fulltext":[{"header":"Background","content":"\u003cp\u003eData from the Global Burden of Disease Study (GBD) has demonstrated that stroke has become the second leading cause of death and the third leading cause of disability worldwide\u003csup\u003e[1]\u003c/sup\u003e, as well as the primary cause of mortality and disability among adults in China\u003csup\u003e[2]\u003c/sup\u003e. The incidence of stroke shows a significant age-related increasing trend \u003csup\u003e[3]\u003c/sup\u003e, with a mean age of onset of 65 years; in individuals aged 40 years and above, the age of first stroke onset is concentrated between 60.9 and 63.4 years \u003csup\u003e[2]\u003c/sup\u003e, indicating that the elderly population is the core affected group of stroke. Stroke is characterized by high incidence, high complication rate, high disability rate, high recurrence rate, and high mortality\u003csup\u003e[4]\u003c/sup\u003e. It not only results in multidimensional functional impairments in patients, including motor, sensory, balance, coordination, and cognitive dysfunctions\u003csup\u003e[1]\u003c/sup\u003e, but also imposes an overwhelming socioeconomic burden\u003csup\u003e[5]\u003c/sup\u003e, thereby posing a severe threat to the health and well-being of the elderly population.\u003c/p\u003e\n\u003cp\u003eFrailty is a clinical syndrome occurring in older adults, resulting from the degenerative changes in the physiological functions of multiple systems including the neurological, muscular, endocrine, and immune systems\u003csup\u003e[6]\u003c/sup\u003e. It is characterized by reduced physiological reserve and diminished capacity to cope with stressors \u003csup\u003e[6]\u003c/sup\u003e. The prevalence of frailty among stroke patients ranges from 23.8% to 54.6%\u003csup\u003e[7]\u003c/sup\u003e. Moreover, stroke patients with comorbid frailty are more likely to experience adverse outcomes, such as prolonged hospital stays, physical function deterioration, and elevated 90-day post-stroke mortality\u003csup\u003e[8]\u003c/sup\u003e, which severely impair the rehabilitation progress and prognostic quality. The comprehensive frailty model proposed by Gobbens et al. \u003csup\u003e[9]\u003c/sup\u003esuggests that frailty is a dynamically evolving process throughout the life course, regulated by multiple factors including age, educational level, and lifestyle, and involves physical, somatic, and social dimensions.\u003c/p\u003e\n\u003cp\u003eRehabilitation intervention is a crucial component in improving the prognosis of stroke patients\u003csup\u003e[10]\u003c/sup\u003e. Studies have confirmed that scientific and effective rehabilitation training during the recovery period can significantly slow down the progression of functional disability and accelerate the rehabilitation process in stroke patients\u003csup\u003e[11]\u003c/sup\u003e. Therefore, rehabilitation treatment in the recovery period holds equal clinical significance to acute-phase treatment and preventive intervention. It plays a positive role in maintaining patients\u0026rsquo; healthy living conditions and reducing the disease burden. However, current studies on frailty in older stroke patients are mostly confined to cross-sectional correlation analyses or single-time-point prognostic predictions, lacking in-depth exploration of its dynamic evolutionary process and underlying mechanisms. Such limitations make it difficult to meet the demands of rehabilitation intervention and precise management during the recovery period.\u003c/p\u003e\n\u003cp\u003eIntrinsic Capacity (IC) refers to the comprehensive manifestation of an individual\u0026rsquo;s physical and mental functions at any stage, and serves as the core carrier for achieving healthy aging\u003csup\u003e[12-14]\u003c/sup\u003e. Its core dimensions include five modules: motor function, cognition, vitality, perception, and psychology \u003csup\u003e[12-14]\u003c/sup\u003e. This concept has been incorporated by the World Health Organization (WHO) into the Guidelines for Integrated Care for Older People and the ICOPE Workbook, becoming a core target for elderly health management\u003csup\u003e[13]\u003c/sup\u003e. Existing studies have confirmed that the decline of IC in older adults is closely associated with various adverse health outcomes \u003csup\u003e[15-17]\u003c/sup\u003e. The detection rate of IC decline in older stroke patients during the recovery period has reached 45.34%\u003csup\u003e[18]\u003c/sup\u003e, which not only leads to the deterioration of patients\u0026rsquo; physical functions, worsening of clinical indicators, and excessive consumption of medical resources \u003csup\u003e[19]\u003c/sup\u003e, but also becomes a key bottleneck hindering the achievement of healthy aging. Maintaining and optimizing the IC of patients during the recovery period is an important approach for formulating personalized rehabilitation plans, improving the quality of life in old age, and reducing adverse outcomes\u003csup\u003e[20]\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003eThere is partial overlap and complementarity in the conceptual connotations between IC and frailty\u003csup\u003e[21]\u003c/sup\u003e. Compared with the negative orientation of frailty that focuses on health deficits, IC emphasizes an individual\u0026rsquo;s existing functional potential and possesses positive health attributes\u003csup\u003e[21]\u003c/sup\u003e. Frailty is not the decline of a single organ system, but the result of the interaction between environmental factors and individual physiological reserve\u003csup\u003e[22]\u003c/sup\u003e. When the IC declines to a critical vulnerability threshold, the body cannot maintain homeostasis in the face of minor endogenous or exogenous stressors, ultimately inducing frailty\u003csup\u003e[22]\u003c/sup\u003e. Studies have suggested that the decline of IC can more accurately reflect the frailty characteristics of older adults, and dynamic tracking of changes in IC during the frailty trajectory can uncover more abundant prognostic information \u003csup\u003e[23]\u003c/sup\u003e; however, other studies have shown that IC decline is more likely to occur in the context of frailty\u003csup\u003e[24, 25]\u003c/sup\u003e. Therefore, it is difficult to clarify whether low IC induces or exacerbates frailty, or whether the frailty state inhibits the improvement of IC. Moreover, there is a lack of exploration on the dynamic correlation mechanism between the two at the current stage, ignoring the state fluctuations and mutual influences of individuals at different rehabilitation stages. Based on this, this study adopts a longitudinal follow-up design to analyze the bidirectional predictive relationship between the two and clarify the causal chain, which has important theoretical and practical value for accurately identifying high-risk groups of frailty and formulating early intervention strategies centered on improving IC.\u003c/p\u003e\n\u003cp\u003ePhysical Resilience (PR) refers to an individual\u0026rsquo;s ability to achieve functional recovery or optimization when confronting age-related injuries or diseases\u003csup\u003e[26]\u003c/sup\u003e. It can effectively predict the long-term health status and lifespan of older adults, and serves as a key entry point for promoting successful aging\u003csup\u003e[27]\u003c/sup\u003e. Monitoring of functional change trajectories is regarded as the \u0026quot;gold standard\u0026quot; for the quantitative assessment of PR\u003csup\u003e[28]\u003c/sup\u003e. Kolk et al.\u003csup\u003e[29]\u003c/sup\u003econstructed trajectories of PR changes by retrospectively evaluating the Activities of Daily Living (ADL) of older adults hospitalized due to acute diseases at 2 weeks before admission and 3 months after admission. However, this method relies on historical stressor trajectory data, and the lack of real-time monitoring limits the reliability of the results \u003csup\u003e[28]\u003c/sup\u003e. Clinically, frailty is often considered an external manifestation of low PR\u003csup\u003e[30]\u003c/sup\u003e. Although there is an association between the two, there are essential differences in their conceptual nature: PR runs through the entire life course, while frailty mainly occurs in old age\u003csup\u003e[30]\u003c/sup\u003e; PR focuses on the accumulation of positive health attributes, whereas frailty is characterized by health deficits and functional limitations\u003csup\u003e[31]\u003c/sup\u003e. Therefore, PR is recognized as an early and sensitive indicator for predicting healthy aging\u003csup\u003e[32]\u003c/sup\u003e. Existing studies have confirmed the correlation between PR and frailty\u003csup\u003e[33]\u003c/sup\u003e, but the causal temporal relationship between them remains unclear. It is urgent to break through the limitations of static analysis, reveal the dynamic interaction rules of the two in the time dimension, and provide evidence-based basis for early frailty screening and functional preservation interventions.\u003c/p\u003e\n\u003cp\u003eThere is a close association between PR and IC. Both characterize the body\u0026rsquo;s reserve capacity, emphasize the positive health attributes of older adults, and are regulated by external environmental factors, yet they cannot be equated. Some scholars have proposed that IC can serve as a high-level comprehensive indicator of physiological reserve, and its impact on PR may be achieved through a mediating effect\u003csup\u003e[34]\u003c/sup\u003e. Wu et al.\u003csup\u003e[35]\u003c/sup\u003e confirmed that individuals with high PR often possess good IC, which can effectively adapt to and mitigate cumulative systemic damage. Chhetri et al.\u003csup\u003e[36]\u003c/sup\u003e further pointed out that IC is a core determinant of PR. However, a study suggested that a high level of IC does not necessarily equate to strong PR, indicating a complex dynamic association between the two\u003csup\u003e[37]\u003c/sup\u003e. Their quantitative relationship and mechanism of action still require in-depth exploration.\u003c/p\u003e\n\u003cp\u003eIn summary, IC, PR, and frailty all focus on aging-related reserve capacity, and there exists a potential dynamic interactive relationship among the three\u003csup\u003e[38]\u003c/sup\u003e. Whitson et al.\u003csup\u003e[28]\u003c/sup\u003e first constructed a structural model of PR in 2016. On this basis, Chhetri et al.\u003csup\u003e[36]\u003c/sup\u003e and Li et al.\u003csup\u003e[39]\u003c/sup\u003e optimized the model by integrating the association between IC and frailty, clarifying a pathway framework that takes PR as the link and integrates pre-existing influencing factors, exposure to health stressors, and aging outcomes. Although existing studies have initially confirmed the correlation among the three, there are significant limitations: first, the research objects are mostly the general elderly population, with few focusing on the special group of older adults in the recovery period of stroke; second, the existing designs are difficult to reveal the causal temporal relationship and dynamic interaction mechanism among the three. Based on the pathophysiological characteristics of older adults in the recovery period of stroke, this study adopts a cross-lagged model to systematically explore the dynamic causal relationship and temporal action pathway among IC, PR, and frailty. The conduct of this study, on the one hand, can fill the gap in longitudinal mechanism research on the three in older adults during the stroke recovery period and enrich the theoretical system related to aging reserve capacity; on the other hand, it can accurately locate intervention targets and temporal nodes, provide empirical support for formulating frailty screening programs and phased intervention strategies that are consistent with the rehabilitation process, and have important public health value for improving the health prognosis of older adults in the stroke recovery period and reducing the medical burden.\u003c/p\u003e"},{"header":"Materials and methods","content":"\u003cp\u003e\u003cstrong\u003eStudy design and participants\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn the sample size calculation of this study, the measured data obtained from the pilot study were used as the basis for effect size estimation\u003csup\u003e[40]\u003c/sup\u003e. A total of 300 subjects were included in the pilot study, and cross-sectional measurements were conducted using the IC Questionnaire and the FRAIL Scale. The results showed a negative correlation between IC score and FRAIL score (r=-0.084, P\u0026lt;0.001). Based on this, the correlation coefficient was converted into an effect size according to the formula f\u0026sup2;=r\u0026sup2;/(1-r\u0026sup2;)\u003csup\u003e[41]\u003c/sup\u003e. Subsequently, G*Power 3.1 software\u003csup\u003e[42]\u003c/sup\u003e was used to calculate the sample size based on the repeated measures analysis of variance (ANOVA) model. The parameters were set as follows: 3 repeated measurements, estimated effect size f=0.08, significance level \u0026alpha;=0.05, and test power (1-\u0026beta;)=0.95. The calculated basic sample size was 404. Considering a further 10% invalid questionnaires, the minimum sample size required for this study was finally determined to be 450.\u003c/p\u003e\n\u003cp\u003eFrom November 2024 to November 2025, convenience sampling was used to select stroke patients admitted to the Department of Neurology of 4 Grade A tertiary general hospitals in Anhui Province as the research subjects. Inclusion criteria: (1) Meeting the diagnostic criteria for stroke and confirmed by cranial CT or MRI; (2) Aged \u0026gt; 60 years; (3) In the stroke recovery period, with clear consciousness and stable condition; (4) Capable of effective verbal and written communication; (5) Voluntarily participating after being informed of the study and signing the informed consent form. Exclusion criteria: (1) Severe hearing or language expression disorders; (2) Patients with severe heart, liver, kidney function impairment or advanced malignant tumors. This research adhered to the guidelines of the Declaration of Helsinki and received approval from the Ethics Committee of Bengbu Medical University (Approval No. 2025-184). All participants provided written informed consent.\u003c/p\u003e\n\u003cp\u003eIn accordance with relevant guidelines\u003csup\u003e[43]\u003c/sup\u003e, data were collected at three time points in this study: at discharge (T1), 3 months after discharge (T2), and 6 months after discharge (T3). The research team consisted of 2 neurosurgical nurses who had received unified training and passed the assessment. Prior to the survey, informed consent was obtained from the respondents, and the purpose of the survey and the principle of confidentiality were explained to each respondent using unified guidelines. The initial survey at T1 was conducted through on-site questionnaires to ensure that the investigators could clearly fill in the relevant instructions on precautions. Follow-up surveys at T2 and T3 after discharge were carried out through telephone, WeChat, hospital outpatient visits, home visits, and other methods, and the appropriate follow-up location and time were arranged according to the actual situation of the patients. All data were double-checked and entered according to unified standards. If there were doubts about the answers or missing responses, the researchers themselves confirmed with the respondents by telephone or other means. If any respondent withdrew midway during the survey, the survey data were treated as invalid. A total of 450 elderly stroke patients were surveyed in this study. At T1, 450 valid questionnaires were recovered. During the T2 follow-up, 8 cases were lost to follow-up (2 cases lost contact, 3 cases died, 3 cases refused). During the T3 follow-up, 11 cases were lost to follow-up (3 cases lost contact, 1 case died, 4 cases refused, 3 cases with extremely poor physical condition). A total of 19 cases were lost to follow-up, and finally, data from 431 cases were valid, with an effective recovery rate of 95.78%.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eIntrinsic Capacity (IC)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn 2019, the World Health Organization (WHO) developed a screening tool consisting of 5 dimensions and 9 indicators to assess the decline in intrinsic capacity\u0026nbsp;\u003csup\u003e[44]\u003c/sup\u003e. The dimensions and indicators are defined as follows:（1）Locomotion: Impaired locomotion is identified by failure in the 5-time chair stand test, i.e., inability to complete 5 repetitions of standing up and sitting down within 14 seconds.（2）Vitality: It refers to unintended weight loss of more than 3 kg within the past 90 days or loss of appetite.（3）Sensory: This dimension encompasses vision and hearing, focusing on whether poor eyesight or hearing impairs daily living activities.（4）Cognition: Cognitive decline is determined by incorrect responses to time or orientation questions, or failure to recall 3 words as required.（5）Psychological: Depression is defined as experiencing low mood, hopelessness, or loss of interest in all activities over the past 14 days.Each item is scored on a binary scale: a \u0026quot;Yes\u0026quot; response is assigned 0 point, while a \u0026quot;No\u0026quot; response is assigned 1 point. The total score ranges from 0 to 5, with higher scores indicating higher levels of intrinsic capacity. The ICOPE screening tool has been validated by domestic scholars and demonstrated good applicability in the Chinese population\u0026nbsp;\u003csup\u003e[13]\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eThe Physical Resilience Instrument for Older Adults (PRIFOR)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe scale was developed by Hu et al.\u003csup\u003e[45]\u003c/sup\u003e, which is used to assess the PR of older adults under acute stressors. Li Jiaxin et al.\u003csup\u003e[46]\u003c/sup\u003e translated it into a simplified Chinese version, including 3 dimensions: Positive Thinking (4 items), Coping and Adjusting Lifestyle (7 items), and Belief and Hope Attitude (5 items). A 5-point Likert scale was used, with scores ranging from 1 to 5 from \u0026quot;Strongly Disagree\u0026quot; to \u0026quot;Strongly Agree\u0026quot;. Higher scores indicate higher levels of PR. The reliability and validity of the scale in this study were verified.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eThe FRAIL Scale\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe scalewas proposed by experts from the International Working Group on Nutrition, Health and Aging\u003csup\u003e[47]\u003c/sup\u003e. It is a 5-item scale, with 1 point assigned for \u0026quot;Yes\u0026quot; and 0 point for \u0026quot;No\u0026quot; for each item. The total score ranges from 0 to 5: 1-2 points indicate pre-frailty, and 3 points or more indicate frailty.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStatistical analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSPSS 25.0 software was used for descriptive statistics and Pearson correlation analysis of the scores of the IC, PR, and FRAIL measured at three time points. Mplus 8.3 software was employed to test the longitudinal measurement invariance of the IC , PR, and FRAIL, and a cross-lagged model was constructed to examine the relationships among IC, PR, and Frailty. The bootstrap method with 2000 repeated samplings was used to test the longitudinal mediating effect of PR between IC and Frailty. The Harman\u0026apos;s single-factor test was applied to conduct factor analysis on all items of variables at T1, T2, and T3 respectively. The results showed that three factors with eigenvalues greater than 1 were extracted at all three time points, and the explanatory rates of the largest common factor were 21.25%, 20.71%, and 22.45% respectively, indicating that there was no obvious common method bias in this study.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003e\u003cstrong\u003eCharacteristics of the participants\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA total of 431 elderly patients with stroke in the recovery stage were recruited, with an age range of 60\u0026ndash;85 years and a mean age of 70.33 \u0026plusmn; 5.119 years. Among them, there were 325 males and 106 females; 281 were from rural areas, 96 from towns and 54 from cities; 405 were married, 16 divorced, 7 widowed and 3 unmarried; 95 had an educational level of primary school or below, 292 had middle school education and 44 had college education or above; 319 lived with spouses, 40 lived alone, 54 lived with children and 18 had other living arrangements; in terms of monthly per capita household income, 35 cases were \u0026le; 1500 yuan, 207 cases were in the range of 1501\u0026ndash;3000 yuan, 162 cases were 3001\u0026ndash;4500 yuan and 27 cases were \u0026gt; 4500 yuan; regarding stroke type, 184 cases were ischemic stroke, 171 cases were intracerebral hemorrhage and 76 cases were subarachnoid hemorrhage; 115 patients had a fall history in the past year while 316 did not; 132 received regular rehabilitation treatment or exercise and 299 did not; 301 had a history of smoking and drinking and 130 did not; in terms of the number of comorbid chronic diseases, 26 cases had more than 3 chronic diseases, 330 cases had 1\u0026ndash;3 chronic diseases and 75 cases had no chronic diseases.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDescriptive Statistics and Correlation Analysis of Variables\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe correlation analysis results demonstrated that, except for the T1P and T3IC correlation coefficients which were not statistically significant, the pairwise correlations of IC, PR, and decay scores at all three time points were statistically significant. Among them, the FRAIL scores were negatively correlated with PR scores(\u003cem\u003er\u003c/em\u003e=-0.1,00~-0.628) and IC scores(\u003cem\u003er\u003c/em\u003e=-0.136~-0.427), while PR scores were positively correlated with IC scores(\u003cem\u003er\u003c/em\u003e=0.146~0.644) (Table 1).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eLongitudinal Measurement Invariance\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eConfigural Invariance, Metric Invariance, and Scalar Invariance models were established respectively for the item scores of the IC, PR, and FRAIL at the three time points. The results are shown in Table 2. All models exhibited good fit (CFI \u0026gt; 0.90, TLI \u0026gt; 0.90, RMSEA \u0026lt; 0.08), and the changes in fit indices of the nested models were all less than 0.01, indicating that the research instruments met the assumption of longitudinal measurement invariance.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCross-Lagged Analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAge was included as a control variable to construct a cross-lagged model of IC item scores and FRAIL scores. All fit indices of the model met psychometric requirements (\u0026chi;\u0026sup2;=104, df =18, \u0026chi;\u0026sup2;/df =5.778, CFI = 0.922, TLI = 0.900, RMSEA=0.046). Cross-lagged analysis showed (Figure 1) that IC scores and FRAIL scores had bidirectional predictive effects (\u003cem\u003e\u0026beta;\u003c/em\u003e=-0.055 to-0.298, both \u003cem\u003eP\u003c/em\u003e\u0026lt;0.05).\u003c/p\u003e\n\u003cp\u003eFigure 1 Cross-lagged Model of Intrinsic Capacity and Frailty in Older Adults with Stroke in Recovery Period\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eLongitudinal mediating effect analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAge was included as a control variable to construct a cross-lagged model of IC scores, PR scores, and FRAIL scores. All fit indices of the model met psychometric requirements (\u0026chi;\u0026sup2;=102.244, df =12, \u0026chi;\u0026sup2;/df =8.520, CFI = 0.922, TLI = 0.904, RMSEA=0.052). Specifically, T1 IC \u0026nbsp;scores positively predicted T2 PR and T3 FRAIL scores ; T1 PR scores negatively predicted T2 FRAIL scores, positively predicted T2 IC scores; T1 FRAIL scores negatively predicted T2 PR scores and positively predicted T2 FRAIL scores; T2 IC scores positively predicted T3 PR scores; T2 PR scores negatively predicted T3 FRAIL scores ; T2 FRAIL scores negatively predicted T3 PR scores(Figure 2).\u003c/p\u003e\n\u003cp\u003eFurthermore, the bootstrap method was used to test the longitudinal mediating effect of PR between IC and Frailty, with age as the control variable. The results showed that the indirect effect of T2 PR scores between T1 IC scores and T3 FRAIL scores was -0.078 (95%CI=-0.168～-0.074), the direct effect was -0.246 (95%CI=-0.481～-0.252), the total effect was -0.324 (95% CI = -0.583～-0.374), and the mediating effect accounted for 24.07%.\u003c/p\u003e\n\u003cp\u003eFigure 2 Cross-lagged Mediation Model of IC, PR and Frailty in Older Adults with Stroke in Recovery Period\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis study conducted three follow-up surveys over 6 months on IC, PR, and Frailty in older adults with stroke in the recovery period, aiming to explore the bidirectional relationship between IC and Frailty as well as the longitudinal mediating role of PR between them. The results of correlation analysis showed that the correlations of IC, PR, and Frailty were significant both at the same time point and across different time points, which was consistent with previous studies\u003csup\u003e[38, 48]\u003c/sup\u003e, indicating an inherent association among the three.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp;The results of the cross-lagged analysis in this study indicated that the intrinsic capacity of elderly patients during the recovery period of stroke exerts a significant negative predictive effect on frailty. This is consistent with previous studies, as the decline in intrinsic capacity is a robust indicator for predicting the occurrence and progression of frailty in the elderly\u003csup\u003e[49]\u003c/sup\u003e. When one or more dimensions of intrinsic capacity are impaired, an individual\u0026apos;s ability to cope with daily challenges and sudden health events is weakened, thereby increasing the risk of frailty\u003csup\u003e[50]\u003c/sup\u003e. For instance, the decline in motor function (e.g., decreased grip strength, slowed gait speed) is a core manifestation of frailty and also a crucial marker of impaired intrinsic capacity\u003csup\u003e[50]\u003c/sup\u003e. In addition, cognitive impairment (e.g., memory loss, inattention) can affect the elderly\u0026apos;s self-management abilities and social participation, further exacerbating the progression of frailty\u003csup\u003e[51]\u003c/sup\u003e. When a stroke occurs, elderly individuals with higher intrinsic capacity can better mobilize their \u0026quot;functional capital\u0026quot;\u0026nbsp;\u003csup\u003e[52]\u003c/sup\u003e\u0026mdash;for example, performing rehabilitation training through strong muscle strength, understanding and executing rehabilitation instructions by virtue of good cognitive function, and coping with the challenges brought by the disease with a positive psychological state\u003csup\u003e[53]\u003c/sup\u003e. When the reserve of intrinsic capacity is sufficient, even in the face of stressors such as illness or injury, the elderly can better maintain physiological homeostasis and achieve functional reconstruction, thereby delaying or avoiding the occurrence of frailty\u003csup\u003e[54]\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003eThis study also found that frailty in elderly patients during the recovery period of stroke also has a significant negative predictive effect on intrinsic capacity. This indicates that there is a complex bidirectional relationship between the two, which is consistent with previous studies\u003csup\u003e[55]\u003c/sup\u003e. Frailty forms a self-reinforcing loop through multiple dimensional pathways such as inflammation, psychological depression, and activity restriction, leading to the continuous decline of IC\u003csup\u003e[24]\u003c/sup\u003e. Frailty is characterized by the exhaustion of physiological reserve and multisystem dysfunction, which directly results in a further decline in intrinsic capacity\u003csup\u003e[24]\u003c/sup\u003e. Multiple factors such as physical activity, bone mineral density, bone diseases, heart rate, blood pressure, oxidative stress, smoking, lifestyle, nutrition, self-efficacy, and depression are associated with aging and physical activity, among which sarcopenia is a disease closely related to frailty and healthy muscle aging\u003csup\u003e[56]\u003c/sup\u003e. In addition, frailty may indirectly impair the psychological and social dimensions of intrinsic capacity by affecting mood, cognition, and social participation\u003csup\u003e[57]\u003c/sup\u003e. This negative impact may lead to reduced activity and social isolation in the elderly, ultimately accelerating the comprehensive degradation of intrinsic capacity\u003csup\u003e[58]\u003c/sup\u003e. This finding challenges the traditional linear view that regards frailty as a result of IC decline, suggesting that clinical interventions need to simultaneously focus on the synergistic improvement of both.\u003c/p\u003e\n\u003cp\u003eFurther longitudinal mediation analysis results showed that T2 PR played a mediating role in the predictive pathway of T1 IC on T3 Frailty. This pathway reveals a \u0026quot;protective mechanism\u0026quot;: a higher initial level of IC provides the body with a kind of \u0026quot;redundancy\u0026quot;, enabling it to mobilize more resources for repair when facing environmental stress, thereby delaying the occurrence of Frailty\u003csup\u003e[44]\u003c/sup\u003e. In addition, it verifies the progressive protective logic of \u0026quot;neuroregulation - physical adaptation - functional maintenance\u0026quot; at the neural mechanism level. IC provides the foundation for PR by maintaining brain region functional connectivity, neurotransmitter balance, and neuroendocrine stability\u003csup\u003e[59]\u003c/sup\u003e. PR serves as an intermediate carrier for IC to exert its protective effect\u003csup\u003e[36]\u003c/sup\u003e. PR is a positive physiological adaptation process; by enhancing neuroplasticity, it helps individuals reorganize neural networks when facing chronic stress, preventing toxic damage caused by excessive activation of the HPA axis\u003csup\u003e[60]\u003c/sup\u003e. Effective Resilience acts as a Buffer, blocking the destructive effects of long-term stress hormones (such as cortisol) on the cognitive and immune systems, thereby delaying the pathological progression of Frailty\u003csup\u003e[61]\u003c/sup\u003e.This finding provides precise intervention targets for the Frailty in the elderly, and has both theoretical expansion and clinical practice value.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStrengths and limitations of this study\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study adopted a three-phase longitudinal follow-up design and focused on the special population of older adults in the recovery period of stroke, clarifying the bidirectional predictive and mediating relationships among IC, PR and frailty. This finding makes up for the limitation of previous studies that only focused on the direct association between the two, and deepens the understanding of the dynamic correlation between physiological decline and IC in the elderly.By applying cross-lagged and mediation models, it reveals the temporal effect pathways among variables and provides a theoretical basis for precise intervention. Age was strictly controlled as a confounding variable to ensure the reliability of the results, and the findings possess both theoretical expansion and clinical practical value.\u003c/p\u003e\n\u003cp\u003eThis study has the following limitations: First, the exploration of moderating variables in the bidirectional pathways is insufficient. Except for age, the impacts of potential moderating factors such as gender, social support, and lifestyle on the strength of relationships among variables remain unclear. In the future, multi-center, large-sample, and cross-regional longitudinal studies are needed to include groups with different demographic characteristics and social backgrounds, and add moderating variable analysis to clarify group differences, thereby providing a basis for precise interventions. Second, the mechanism verification lacks direct objective evidence. The current mechanism analysis is mostly derived based on existing studies, and objective detection data such as neuroimaging and neurobiochemistry of the study samples are not included, making it difficult to accurately quantify the mechanism associations. In subsequent studies, relevant detection technologies should be combined to further verify the core targets of neural mechanisms and consolidate the theoretical foundation. Third, the sample representativeness is limited, and the generalizability of the conclusions needs to be further verified by multi-center, large-sample, and cross-regional cohort studies. Fourth, the revelation of dynamic associations is insufficient. The study only conducts analysis through 3 time points, which is difficult to reflect the dynamic fluctuations and interactive effects of IC, PR, and Frailty. In the future, it is necessary to extend the research cycle, increase the number of time points, explore the dynamic change rules of variables, and refine the temporal characteristics of bidirectional effects.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThrough a 3-phase longitudinal follow-up design, this study found a bidirectional predictive relationship between IC and Frailty, and simultaneously revealed that PR plays a mediating role between them. This finding not only enriches the theoretical system of \u0026quot;Capacity-Resilience-Frailty\u0026quot; in the field of geriatric health but also provides a new basis for the clinical formulation of targeted intervention strategies.\u003c/p\u003e\n"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors would like to thank all patients for their voluntarily participating and the staff for their help with data collection in this study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor Contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eYanfang Zhang\u003c/strong\u003e: Conceptualization, data curation, formal analysis, investigation, writing original draft, and writing review editing. \u003cstrong\u003eXiaomei Jia, Yuanyuan Yub, Manman Huc, Liangliang Sund, Lihua Wange,Long Zhao\u003c/strong\u003e: Data curation. investigation, methodology, and writing review and editing.\u003cstrong\u003eXiumu Yang\u003c/strong\u003e:funding acquisition, methodology, project administration, supervision.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe author(s) declare that financial support was received for\u0026nbsp;the research and/or publication of this article. This work was\u0026nbsp;supported by University Scientific Research Project of Bengbu Medical University ( 2024byzd163sk; 2023byfy142sk ;2022byzd130sk),\u0026nbsp;Longhu Talent Project of Bengbu Medical University(\u0026nbsp;LH250201001\u0026nbsp;),\u0026nbsp;Key project of humanities and social sciences\u0026nbsp;of\u0026nbsp;Anhui Provincial Department of Education(\u0026nbsp;2024AH040341;2023AH051903\u0026nbsp;).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData Availability Statement\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe anonymized data that support the findings of this study\u0026nbsp;were\u0026nbsp;available from the author (Yangfang Zhang) upon reasonable request. The data\u0026nbsp;were\u0026nbsp;not publicly available due to privacy and ethical restriction.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis research adhered to the guidelines of the Declaration of Helsinki and received approval from the Ethics Committee of Bengbu Medical University (Approval No. 2025-184). All participants provided written informed consent.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNone.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict Of Interest Statement\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThere\u0026nbsp;were\u0026nbsp;no financial disclosures or conflicts of interest to disclose.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eORCID\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eYanfang Zhang \u0026nbsp; https://orcid.org/0009-0002-1080-0565\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eGBD 2019 Stroke Collaborators. \u003cem\u003eGlobal, regional, and national burden of stroke and its risk factors, 1990-2019: a systematic analysis for the Global Burden of Disease Study 2019.\u003c/em\u003e Lancet Neurol. 2021. \u003cstrong\u003e20\u003c/strong\u003e(10): 795\u0026ndash;820 DOI: 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section.\u003c/p\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":"bmc-geriatrics","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bgtc","sideBox":"Learn more about [BMC Geriatrics](http://bmcgeriatr.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bgtc/default.aspx","title":"BMC Geriatrics","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Elder, Stroke,Intrinsic Capacity, Physical Resilience, Frailty,Cross-Lagged Panel Study","lastPublishedDoi":"10.21203/rs.3.rs-8446143/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8446143/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground\u003c/strong\u003e The existing designs are difficult to reveal the causal temporal relationship and dynamic interaction mechanism among intrinsic capacity(IC), physical resilience(PR), and frailty.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eObjective \u003c/strong\u003eThis study aims to investigate the longitudinal relationships between IC, PR, and frailty in elderly stroke patients during the rehabilitation phase, and to reveal their potential mediating roles.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods\u003c/strong\u003e From November 2024 to November 2025, this study employed convenience sampling to select stroke patients admitted to the neurology departments of four Grade A tertiary general hospitals in Anhui Province as research subjects. The IC questionnaire, The Physical Resilience Instrument for Older Adults (PRIFOR), and The FRAIL Scale were used as measurement tools, with observations conducted at three time points: discharge (T1),3 months post-discharge (T2), and 6 months post-discharge (T3). The cross-lag model was used to analyze the causal relationships among IC, PR, and frailty in elderly stroke patients during stroke recovery.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults\u003c/strong\u003e the FRAIL scores were negatively correlated with PR scores(\u003cem\u003er\u003c/em\u003e=-0.1,00~-0.628) and IC scores(\u003cem\u003er\u003c/em\u003e=-0.136~-0.427), while PR scores were positively correlated with IC scores(\u003cem\u003er\u003c/em\u003e=0.146~0.644).Cross-lagged analysis showed (Figure 1) that IC scores and FRAIL scores had bidirectional predictive effects (\u003cem\u003eβ\u003c/em\u003e=-0.055 to-0.298, both \u003cem\u003eP\u003c/em\u003e\u0026lt;0.05).Longitudinal mediating effect analysis showed that indirect effect of T2 PR scores between T1 IC scores and T3 FRAIL scores was -0.078 (95%CI=-0.168～-0.074), the direct effect was -0.246 (95%CI=-0.481～-0.252), the total effect was -0.324 (95% CI = -0.583～-0.374), and the mediating effect accounted for 24.07%.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusions\u003c/strong\u003e The lower the level of IC, the higher the degree of frailty in the elderly patients with post-stroke recovery, and the PR plays a mediating role between the two.\u003c/p\u003e","manuscriptTitle":"Relationship between Intrinsic Capacity, Physical Resilience and Frailty among elderly patients during stroke recovery: A cross-lagged panel study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-02-09 12:47:29","doi":"10.21203/rs.3.rs-8446143/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-03-10T08:32:28+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-02-16T20:01:26+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-02-15T06:02:58+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"193218744946099710826864985655690760554","date":"2026-02-13T16:03:43+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"275296205537810313599926934828940325708","date":"2026-02-07T13:16:43+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"200787290969803865805014884405070457750","date":"2026-02-07T02:25:38+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-02-05T19:11:51+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"60990782787883655665199812077112369410","date":"2026-02-05T09:37:53+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-02-05T08:27:20+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-02-03T06:33:14+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2026-01-14T09:47:38+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-01-14T07:47:39+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Geriatrics","date":"2026-01-14T07:39:05+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-geriatrics","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bgtc","sideBox":"Learn more about [BMC Geriatrics](http://bmcgeriatr.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bgtc/default.aspx","title":"BMC Geriatrics","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"849510a8-13d2-4edc-a4ac-c752be6b1b4e","owner":[],"postedDate":"February 9th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-03-29T17:09:10+00:00","versionOfRecord":[],"versionCreatedAt":"2026-02-09 12:47:29","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8446143","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8446143","identity":"rs-8446143","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}