Abstract / Summary
Parkinson’s disease (PD) is a major cause of functional disability among older adults, yet the role of patients’ subjective health perceptions in this association remains poorly quantified. This study aimed to examine the independent association between PD and impairments in basic (BADL) and instrumental activities of daily living (IADL), and to decompose the relative contributions of multi-domain factors—with a primary focus on self-rated health—in a nationally representative Chinese population. This cross-sectional analysis used data from the 2020 wave of the China Health and Retirement Longitudinal Study (CHARLS), enrolling 17,311 community-dwelling adults aged ≥ 45 years, including 196 with physician-diagnosed PD. Multivariate logistic regression with sequential adjustment was applied to estimate the independent association of PD with BADL/IADL disability. A stepwise effect-size decomposition approach was employed to quantify the percentage contribution of each covariate block (sociodemographic, lifestyle, and clinical factors) to the total PD–disability effect, with particular emphasis on self-rated health. PD was independently associated with significantly elevated risks of BADL impairment (OR = 2.73, 95%CI: 1.99–3.75) and IADL impairment (OR = 1.88, 95%CI: 1.37–2.60) after full adjustment. Sequential effect decomposition revealed that self-rated health accounted for the largest attenuation of the association, explaining 26.5% of the PD–BADL effect and 29.8% of the PD–IADL effect—far exceeding the contributions of depression, multimorbidity, and cognitive dysfunction. Subgroup analyses confirmed the robustness of these findings across all strata (all P for interaction > 0.05). Self-rated health emerges as the dominant explanatory factor in the PD–functional disability pathway, outperforming conventional clinical indicators. These findings advocate a paradigm shift from symptom-focused management toward integrated care that prioritizes patients’ subjective health perceptions. We recommend incorporating routine self-rated health assessment and targeted psycho-behavioral interventions into standard PD care as a promising strategy to slow progressive functional decline.