The Incidence of Parkinson’s Disease: A Systematic Review and Meta-Analysis

Background: Parkinson’s disease (PD) is a common neurodegenerative disorder. Epidemiological studies on the incidence of PD are important to better understand the risk factors for PD and determine the condition’s natural history. Objective: This systematic review and meta-analysis examine the incidence of PD and its variation by age and gender. Methods: We searched MEDLINE and EMBASE for epidemiologic studies of PD from 2001 to 2014, as a previously published systematic review included studies published until 2001. Data were analyzed separately for age group and gender, and meta-regression was used to determine whether a significant difference was present between groups. Results: Twenty-seven studies were included in the analysis. Metaanalysis of international studies showed rising incidence with age in both men and women. Significant heterogeneity was observed in the 80+ group, which may be explained by methodological differences between studies. While males had a higher incidence of PD in all age groups, this difference was only statistically significant for those in the age range Received: September 22, 2015 Accepted: March 11, 2016 Published online: April 23, 2016 Tamara Pringsheim, MD Department of Clinical Neurosciences University of Calgary 3280 Hospital Drive NW, Calgary AB T2N 4Z6 (Canada) E-Mail tmprings @ ucalgary.ca © 2016 S. Karger AG, Basel 0251–5350/16/0464–0292$39.50/0