Implementing the WHO ICOPE Framework in a Super-Aged Society: Identifying Intrinsic Capacity Thresholds for Community-Based Depressive Risk Screening in Taiwan

Background As global populations age, shifting from disease-centered to function-centered care is essential for healthy aging. The World Health Organization’s Integrated Care for Older People (ICOPE) framework identifies intrinsic capacity (IC) as a holistic predictor of health outcomes. However, evidence regarding the specific dose–response relationship between non-psychological IC impairments and depressive risk, along with actionable screening thresholds, remains limited in community settings. This study aimed to investigate this relationship and identify an optimal screening threshold for risk stratification in a super-aged society. Methods A secondary analysis was conducted on community-based health assessment data (collected 2023–2025) retrieved from the Health Promotion Administration (HPA), Ministry of Health and Welfare, Taiwan. The sample included 2,221 community-dwelling older adults (aged ≥ 65 years) in rural Taiwan. Intrinsic capacity was assessed across five non-psychological domains: cognition, mobility, nutrition, vision, and hearing. Depressive risk was evaluated using standardized ICOPE screening tools. Multivariable logistic regression, restricted cubic spline (RCS) analysis, and receiver operating characteristic (ROC) analysis were employed to evaluate the dose–response relationship and identify optimal cut-points. Decision curve analysis (DCA) assessed clinical utility. Results A robust linear dose–response relationship was observed; depressive risk increased significantly with the accumulation of IC impairments (p for trend < 0.001). ROC analysis identified a threshold of ≥ 2 impairments (IC_count ≥ 2) as the optimal cut-point (Youden index = 0.22, AUC = 0.64). After adjusting for age, sex, chronic diseases, and community factors, individuals with ≥ 2 impairments had a 2.53-fold higher risk of depression (95% CI: 1.77–3.62, p < 0.001) compared to those with fewer impairments. The threshold demonstrated a high negative predictive value (0.96), and DCA confirmed a positive net benefit for clinical decision-making. Conclusions Non-psychological IC impairments are strong, independent predictors of depressive risk. The identification of IC ≥ 2 as a pragmatic screening threshold provides an evidence-based criterion for community-based risk stratification. These findings support the integration of IC assessment into routine public health screenings and social prescribing programs to facilitate early mental health intervention in super-aged societies.