The natural history of Parkinson's disease in the province of Segovia: mortality in a longitudinal study (20-year follow-up)

Objective We determined mortality rates and predictors of survival in 273 patients with Parkinson's disease based on a 20-year follow-up longitudinal study. Material and methods We examined 273 patients with Parkinson's disease during a 20-year follow-up, recruited between 1978 and 1998. All patients were regularly followed at the Department of Neurology until December 31, 1998, or death. Results By then, 69 patients had died, crude mortality was rate 4.43, and standardized mortality ratio for the total patient group was 1.39 (95% CI, 1.101.50). As Parkinson's disease is a chronic progressive disorder in adult life, disease-related mortality would be expected to increase in later stages after 15 or 20years. Mean age at death in our cohort was 78.27 (95% CI, 76.9079.20). Median time of death was 11years (95% CI, 9.5012.49). Independent predictors of mortality during the follow-up were age at onset (hazard ratio, 1.05; 95% CI, 1.011.09; P=0.01), clinical form akinesia and rigidity (hazard ratio, 2.20; 95% CI, 1.064.88; P=0.03) and treatment with dopaminergic agonist (hazard ratio, 0.49; 95% CI, 0.231.03; P=0.06). Cardiovascular disease was the most frequent cause of death in 42%. Conclusions This study suggests a link between mortality with age of onset and treatment without dopamine agonists as initial treatment. So, there is an association between decreased mortality and tremor as initial clinical forms at onset.