Prevalence of orthostatic hypotension in Parkinson's disease: A systematic review and meta-analysis

Background: Although orthostatic hypotension (OH) is recognized as one of the main non-motor symptoms of Parkinson's disease (PD), there is inconsistent evidence about the prevalence of OH in PD. To estimate the prevalence of OH in PD more precisely we conducted a systematic review of the literature. Methods: From PubMed and Embase searches with predefined inclusion criteria, we identified studies published up till December 2009. Prevalence numbers from studies were pooled using a non-linear random-effects meta-analysis. Results: We found 25 studies from which the prevalence of OH could be calculated. The pooled estimate of the point prevalence of OH in PD was 30.1% (95% Cl: 229% to 38.4%). We found a large statistical heterogeneity between studies which could not be reduced by several subgroup analyses. Conclusions: The estimated prevalence of OH in PD is 30%. However, due to the large heterogeneity between studies this pooled estimate should be interpreted with caution. More data from unselected population-based cohorts are needed. (C) 2011 Elsevier Ltd. All rights reserved.