Predictors of Mortality in Nondemented Patients With Parkinson Disease: Motor Symptoms Versus Nonmotor Symptoms

Abstract

Background and Objective: The aim of this study is to identify risk factors for mortality in a community-based cohort of nondemented patients with Parkinson disease (PD) during prospective long-term follow-up, while also comparing the effect of motor complications to nonmotor symptoms (NMS) on risk of mortality. Methods: One hundred forty seven nondemented patients with PD (57.1% males; 70.9 ± 8.6 years old) were included in this 48 month follow-up, longitudinal, single, evaluation study. Motor and therapy-related complications were assessed using the Unified Parkinson’s Disease Rating Scale/part-IV (UPDRS-IV). Non-Motor Symptoms Scale (NMSS) total score was used to assess NMS burden. Cox proportional hazard models were applied to identify independent predictors of mortality during follow-up. Results: Twenty-two patients of 146 (15.1%) died (1 case without information). Both UPDRS-IV and NMSS total scores were higher at baseline in patients with PD who died (3.5 ± 3.1 vs 2.4 ± 2.4, P =.049 and 96.9 ± 58.6 vs 61.9 ± 51.0, P =.004, respectively). Unadjusted hazard ratios (HRs) associated with UPDRS-IV and NMSS total scores among those who died during follow-up were 1.171 (95% confidence interval [CI]: 1.012-1.357; P =.035) and 1.008 (95% CI: 1.002-1.013; P =.006), respectively. Independent predictors of mortality during follow-up after adjusting for other covariates were UPDRS-IV (HR: 1.224; 95% CI: 1.002-1.494; P =.047), age (HR: 1.231; 95% CI: 1104-1.374; P