Prevalence of Parkinson’s disease across North America

• Published in: NPJ Parkinson's Disease Vol. 4; no. 1; pp. 21 - 7
• Main Authors: Marras, C., Beck, J. C., Bower, J. H., Roberts, E., Ritz, B, Ross, G. W., Abbott, R. D., Savica, R., Van Den Eeden, S. K., Willis, A. W., Tanner, CM
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 10.07.2018; Nature Publishing Group
• Subjects: 692/617/375/1718; 692/699/375/1718; Biomedical and Life Sciences; Biomedicine; Estimates; Medicare; Neurology; Neurosciences; Parkinson's disease; Minnesota; California; United States > US; North America
• DOI: 10.1038/s41531-018-0058-0
• ISSN: 2373-8057

Estimates of the prevalence of Parkinson’s disease in North America have varied widely and many estimates are based on small numbers of cases and from small regional subpopulations. We sought to estimate the prevalence of Parkinson’s disease in North America by combining data from a multi-study sampling strategy in diverse geographic regions and/or data sources. Five separate cohort studies in California (2), Minnesota (1), Hawaii USA (1), and Ontario, Canada (1) estimated the prevalence of PD from health-care records (3), active ascertainment through facilities, large group, and neurology practices (1), and longitudinal follow-up of a population cohort (1). US Medicare program data provided complementary estimates for the corresponding regions. Using our age- and sex-specific meta-estimates from California, Minnesota, and Ontario and the US population structure from 2010, we estimate the overall prevalence of PD among those aged ≥45 years to be 572 per 100,000 (95% confidence interval 537–614) that there were 680,000 individuals in the US aged ≥45 years with PD in 2010 and that that number will rise to approximately 930,000 in 2020 and 1,238,000 in 2030 based on the US Census Bureau population projections. Regional variations in prevalence were also observed in both the project results and the Medicare-based calculations with which they were compared. The estimates generated by the Hawaiian study were lower across age categories. These estimates can guide health-care planning but should be considered minimum estimates. Some heterogeneity exists that remains to be understood. Disease prevalence: Measuring the rising tide A large study that combines data from five different projects in four different regions across North America provides an updated estimate of the prevalence of Parkinson’s disease (PD). Connie Marras at Toronto Western Hospital in Canada and colleagues found that PD prevalence among individuals over 45 years of age is higher among men than women and that it increases with age in both sexes. They estimate that the overall prevalence of PD is 572 per 100,000 and that in the US in 2010 there were 680,000 individuals with PD. As life expectancy increases this number is projected to increase to over one million by 2030. These figures, which the authors note should be considered minimum prevalence estimates, warn of the impact that PD will have on North America’s healthcare systems in the near future.