Functional ability index predicts cardiovascular disease and comorbid health outcomes in older Chinese adults: A national longitudinal cohort study

Aging populations face increasing cardiovascular disease (CVD) risks worldwide. However, existing tools often neglect critical functional and environmental determinants that are essential in health assessments. This study evaluated the functional ability index (FAI), which integrates physical, cognitive, and social domains, as a comprehensive predictor of CVD and comorbid outcomes in older Chinese adults.

Analysing 4298 participants from the China Health and Retirement Longitudinal Study (2011-2018), we employed Cox proportional hazards models to assess associations between FAI and CVD, self-rated health, falls, and hospitalization. Additionally, time-dependent analysis and population-attributable fraction (PAF) estimation were utilized to evaluate predictive accuracy and quantify modifiable risk contributions.

High functional ability (FAI ≥ 12) was independently associated with substantially reduced risks of CVD (HR: 0.64, 95% CI: 0.56-0.72), self-rated health (HR: 0.62), falls (HR: 0.75), and hospitalization (HR: 0.73) in fully adjusted models. Time-dependent analysis identified 4 years as the optimal predictive window. Crucially, PAF analysis revealed that non-CVD multimorbidity (-70.2%) and weight loss (-54.9%) were the strongest modifiable contributors to CVD risk. These two factors also consistently remained the dominant determinants for both hospitalization and self-rated health. In contrast, affect (-22.0%) and gait level (-21.0%) emerged as the leading contributors to falls, highlighting distinct functional targets.

As a robust, non-invasive aging tool, the FAI facilitates risk stratification by identifying modifiable indicators-managing chronic conditions, preventing malnutrition, and improving psychological health. This framework provides a practical approach for guiding targeted interventions to reduce cardiovascular burden and promote healthy aging.