Burden of parkinsonism: a population-based study.

Parkinson's disease (PD) is associated with a significant burden of illness and cost to society, which has been difficult to quantify. Our objective was to use linked administrative databases from the population of Ontario, Canada, to assess the prevalence of parkinsonism, physician- and drug-related costs, and hospital utilization for parkinsonian patients compared with age/sex matched controls. An inception cohort of parkinsonian cases from 1993/1994 was age and sex matched (1:2) to controls and followed for 6 years. Patients were identified by the diagnostic code for PD, the use of specific PD drugs, or a combination. The parkinsonian case cohort (15,304) was matched to (30,608) controls that did not have parkinsonism. The age-adjusted prevalence rates were 3.63 for men and for 3.24 women per 1,000 (increased by 5.4% for men and 9.8% for women). Physician costs were 1.4 times more, there were 1.44 times more hospital admissions, admissions were on average 1.19 times longer, and drug costs were 3.0 times more for parkinsonian cases. We conclude that the substantially higher physician and drug costs as well as hospitalization rates compared with controls clearly suggest that parkinsonism is associated with large direct costs to society.