Longitudinal study of mortality predictors in Parkinson's disease in Nigerians

Abstract

Parkinson's disease (PD) has been associated with increased mortality. The mortality in Nigerians has not been described. This study was designed to assess mortality in PD and relate it to gender, age at onset of PD and at baseline, and duration of PD. A case-control study of 28 PD and 28 age- and sex-matched controls from similar geographic locality was conducted. Baseline clinical characteristics of the PD patients and controls were documented at study inception. Cases and controls selected between January and June 1997 were followed up after a 6-year interval (May 2002). The case fatality rate (CFR) in PD was 25% compared to 7.1% in controls (Mantel-Haenszel test, P=0.01). PD survivors (compared to PD patients who died) were significantly younger both at study onset (mean age 59.8+10.3 v. 72.3±6.8; P=0.002) and at onset of PD (mean age 57.3± 10.3 v. 69.3 ±6.5; P=0.003), and had significantly less severe disease at baseline (mean Hoehn & Yahr stage 2.1±0.7 v. 2.9± 1.1; P=0.04). CFR was significantly higher in PD cases aged =70 years at study onset (Mantel-Haenszel test, P=0.004) and at onset of PD (Mantel-Haenszel test, P=0.001), but not in age-matched controls. PD affecting Nigerians is associated with increased mortality as has been demonstrated in other geographic locations. Factors associated with increased mortality include advanced age, older age at onset of PD, and more severe disease.