Intrinsic Capacity Impairment Patterns and their Associations with Unfavorable Medication Utilization: A Nationwide Population-Based Study of 37,993 Community-Dwelling Older Adults

Our aim was to explore the patterns of intrinsic capacity (IC) impairments among community-dwelling older adults and the associations of these different patterns with excessive polypharmacy, potentially inappropriate medications, and adverse drug reactions in a nationwide population-based study. A cross-sectional study included older adults from the Taiwan Integrated Care for Older People (ICOPE) program in 2020. The study subjects comprised 38,308 adults aged 65 years and older who participated in the ICOPE Step 1 screening and assessed six domains of IC following the World Health Organization (WHO) ICOPE approach. Latent class analysis was adopted to identify distinct subgroups with different IC impairments patterns. The associations between different IC impairments patterns and unfavorable medication utilization, including excess polypharmacy (EPP), potentially inappropriate medications (PIMs), and adverse drug reactions (ADRs), were assessed by multivariate logistic regression models. Latent class analysis identified five distinct subgroups with different IC impairment patterns: robust (latent class prevalence: 59.4%), visual impairment (17.7%), physio-cognitive decline (PCD) with sensory impairment (12.3%), depression with cognitive impairment (7.7%), and impairments in all domains (2.9%). Compared to the robust group, all other groups were at higher odds for unfavorable medication utilization. The "depression with cognitive impairment" group (EPP: aOR=4.35, 95% CI 3.52–5.39, p<0.01; PIMs: aOR=2.73, 95% CI 2.46–3.02, p<0.01) and the "impairment in all domains" group (EPP: aOR=9.02, 95% CI 7.16–11.37, p<0.01; PIMs: aOR=3.75, 95% CI 3.24–4.34, p<0.01) remained at higher odds for EPP and PIMs after adjustment. We identified five distinct impairment patterns of IC, and each impairment pattern, particularly the "depression with cognitive impairment" and "impairment in all domains", was associated with higher odds of EPP and PIMs. Further longitudinal and intervention studies are needed to explore long-term outcomes of different impairment pattern and their reversibility.