Prognostic factors for early mortality in Parkinson's disease

Abstract

Introduction: There are few large studies that have evaluated prognostic factors for mortality in Parkinson's disease (PD). This large study aimed to identify demographic and clinical features associated with early mortality in PD.

Methods: PD patients at the National Neuroscience Institute were identified from the Movement Disorders Database from which demographic information and prospectively collected baseline disease characteristics were obtained. All study patients were linked to the Singapore Registry of Birth and Death to obtain information on vital status through December 31, 2012. The prognostic variables analyzed include patient demographics, baseline disease characteristics, and type of PD medication used. Multivariate Cox regression analysis was carried out to identify factors associated with the risk of mortality in PD.

Results: Of the 1786 PD patients identified, 363 (20.3%) had died during the 11-year study period. Median survival time from diagnosis was 15.8 years (range 0.3-31). Factors associated with higher mortality (HR, 95% CI) were older age at diagnosis (1.06, 1.03-1.08), male gender (2.29, 1.57-3.35), Hoehn & Yahr (HY) stage ≥ 2.5 (1.54, 1.07-2.22), UPDRS motor score ≥ 30 (1.63, 1.13-2.35), higher bradykinesia subscores (1.05, 1.01-1.09) and cognitive impairment (2.30, 1.55-3.41).

Conclusions: In the largest study to date evaluating baseline disease characteristics prognostic of mortality risk in PD, we found that male gender, older age at diagnosis, higher baseline HY stage, higher baseline UPDRS motor scores, higher bradykinesia subscores and baseline cognitive impairment were associated with early mortality in PD.

Keywords: Mortality; Parkinson's disease; Prognostic factors; Survival.