Mortality of Parkinson's disease by Hoehn-Yahr stage from community-based and clinic series [Keelung Community-based Integrated Screening (KCIS) no. 17)].

Purpose: We aimed to quantify the mortality reduction by which the early detection of Parkinson's disease (PD) within a community-based study could reduce the number of advanced cases.
Methods: Data used in this study were derived from two community-based surveys and from a clinical series of PD cases identified from a medical centre. The cumulative survival by Hoehn-Yahr (H-Y) scale was estimated and the mortality reduction derived from a community-based survey was predicted.
Results: A total of 117 PD patients were detected through two community-based approaches. By comparing the H-Y stage distribution of screen-detected cases with those from the clinical series, a 22.5% excess in the number of early PD (H-Y stage I and stage II) were identified with screening. The risk ratios of being H-Y stage III or severe for community-based detected cases versus clinical series were 0.49 (95% confidence interval: 0.30-0.78). The total death rate adjusted by H-Y stage distribution was 21% and 28% for cases from community and clinical series, respectively.
Conclusions: The present study revealed that early detection of PD through a community-based survey may reduce 51% incidence of stage III or more severe PD at diagnosis, leading to a 25% reduction in mortality.