Data Sheet 1_The association of polypharmacy with intrinsic capacity: an analysis of the WHO ICOPE pilot data from Lianyungang, China.docx

ObjectiveAs a core indicator of healthy aging, intrinsic capacity (IC) may be adversely impacted by polypharmacy. Leveraging data from the WHO Integrated Care for Older People (ICOPE) pilot in China, this study examines the association between polypharmacy and IC decline in older adults, aiming to provide evidence-based insights for optimizing geriatric pharmacotherapy.
MethodsA cross-sectional analysis was conducted using data from community-dwelling and institutionalized adults aged ≥60 years enrolled at the Lianyungang (LYG) pilot site of the WHO ICOPE China program. Medication histories, demographic characteristics, lifestyle factors, and chronic disease profiles were collected via structured questionnaires. The WHO ICOPE screening tool was employed to assess five IC domains: cognition, mobility, sensory function, nutrition, and psychology. Polypharmacy was defined as concurrent use of ≥5 medications. Multivariable logistic regression models evaluated the polypharmacy-IC decline association, with stratification analyses assessing subgroup heterogeneity.
ResultsThe study enrolled 467 participants, comprising a polypharmacy cohort (≥5 medications, n = 33) and a non-polypharmacy cohort (n = 434). Mean IC score was 3.5 ± 1.5. In unadjusted analyses, polypharmacy is associated with greater odds of IC decline (OR = 2.81, 95% CI: 1.06–7.43, p = 0.037). This association persisted in Model 1 (demographic-adjusted: OR = 2.82, 95% CI: 1.05–7.56, p = 0.039), Model 2 (socioeconomic-adjusted: OR = 3.65, 95% CI: 1.33–9.98, p = 0.012), and Model 3 (functional/geriatric-adjusted: OR = 3.23, 95% CI: 1.13–9.28, p = 0.029). However, in the fully adjusted Model 4 (including comorbidities), the OR attenuated to 2.31 (95% CI: 0.77–6.88, p = 0.134), retaining a positive but non-significant association. After full covariate adjustment, each additional medication was associated with a 22% increase in the likelihood of IC decline (OR = 1.22, 95% CI: 1.01–1.47, p = 0.04). Patients with IC decline demonstrated significantly higher medication counts than those with preserved IC (p < 0.05). Stratified analyses confirmed stable associations across subgroups (all interaction p > 0.05).
ConclusionAn increase in the number of medications used by older adults may be positively associated with a decline in intrinsic capacity (IC). The prevalence of IC decline is significantly higher among individuals taking ≥5 medications compared to those using fewer medications. These findings suggest that polypharmacy is associated with IC decline and could serve as a potential indicator for IC decline. Prospective studies are needed to validate the causal relationship.