Meeting the 24‐Hour Movement Guidelines and Frailty Risk: Evidence From Two Nationally Representative Population Studies and Machine‐Learning Models

AIM: This study aimed to examine the association between meeting the 24-Hour Movement Guideline components-moderate-to-vigorous physical activity (MVPA), sleep duration, and sedentary behavior (SB)-and frailty across two nationally representative populations. METHODS: We analyzed 11 893 National Health and Nutrition Examination Survey (NHANES) participants (2011-2018) and 4823 China Health and Retirement Longitudinal Study (CHARLS) participants (baseline 2011 with follow-up through 2018). The reference category was meeting none of the three guideline components. Cross-sectional associations were examined using multivariable logistic regression, and longitudinal associations were examined using Cox proportional hazards models. Exploratory machine-learning analyses were conducted to evaluate frailty classification and feature importance. RESULTS: In cross-sectional analyses, meeting all three components was associated with lower odds of frailty in NHANES (OR = 0.21; 95% CI, 0.14-0.32) and CHARLS (OR = 0.29; 95% CI, 0.16-0.46). Meeting two-component combinations was also associated with lower odds of frailty in both cohorts. In CHARLS longitudinal analyses, over a median follow-up of 7.0 years, 1457 incident frailty cases occurred. Compared with participants meeting none of the three components, those meeting all three components had a lower hazard of incident frailty (HR = 0.33; 95% CI, 0.27-0.41). In exploratory machine-learning analyses, the Random Forest model showed the highest overall performance, and SHAP analyses identified 24-Hour Movement Guideline adherence and MVPA among relevant features for frailty classification. CONCLUSION: Meeting multiple 24-Hour Movement Guideline components was associated with lower frailty odds and incident frailty hazard. These findings support considering movement behaviors within an integrated 24-h framework.