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



This systematic review and meta-analysis examine the incidence of PD and its variation by age and gender.



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.



Twenty-seven studies were included in the analysis. Meta-analysis 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 60-69 and 70-79 (p < 0.05).



PD incidence generally increases with age, although it may stabilize in those who are 80+.
Department of Clinical Neurosciences, University of Calgary, Calgary, Alta., Canada.
Lauren
L
Hirsch
Nathalie
N
Jette
Alexandra
A
Frolkis
Thomas
T
Steeves
Tamara
T
Pringsheim
D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000453:epidemiology*; D012307:Risk Factors; D012737:Sex Factors