Timing of rehabilitation therapy initiation and all-cause mortality in parkinson’s disease: nationwide cohort study

Rehabilitation is integral to Parkinson’s disease management yet remains underutilised, with limited evidence on long-term survival impact. Using Korean National Health Insurance Service data, we identified 19,153 individuals newly diagnosed with Parkinson’s disease (2006–2023) who received rehabilitative developmental therapy. Stratified by rehabilitation initiation timing and disability severity at initiation, Cox proportional hazards regression estimated adjusted hazard ratios [HR]s for all-cause mortality. Compared with rehabilitation within 1 year of diagnosis, delays of 1–2 years and ≥2 years were associated with 28% (HR 1.28, 95% CI 1.21–1.35) and 44% (HR 1.44, 95% CI 1.37–1.51) higher mortality hazard, respectively. Mortality hazard increased progressively with disability severity (21% for mild-to-moderate, 45% for severe). Earlier rehabilitation consistently reduced mortality across all disability subgroups with a dose-response trend, with no statistically significant interaction between timing and disability severity ( P = 0.503). These findings support systematic rehabilitation referral at Parkinson’s disease diagnosis.