Systematic Review of Prevalence Studies of Progressive Supranuclear Palsy and Corticobasal Syndrome.

BACKGROUND

High-quality prevalence studies are important in estimating the burden of disease in a population, thus informing priority setting, resource allocation, delivery, and use of health services.

OBJECTIVES

This study was undertaken to systematically review the methods and results of previous prevalence studies of progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS) and make recommendations for future studies.

METHODS

A total of 2 authors independently identified original articles that described the prevalence of PSP or CBS using several comprehensive and overlapping search strategies, assessed study quality, and extracted relevant data. Descriptive and pooled analyses were performed as appropriate.

RESULTS

A total of 16 studies were identified in PSP and 9 studies in CBS, with highly heterogeneous methods of case definition, identification, and verification in identified studies. Few studies were deemed of necessary quality or methodological homogeneity to justify a full meta-analysis. In addition, few studies reported age- and sex-stratified results. The best 3 prevalence studies in PSP gave a pooled rate of 7.1 per 100,000 per year, whereas the pooled rate in 2 CBS studies was roughly 3 times lower at 2.3 per 100,000 per year. Based on crude rates, there was little evidence to suggest clear sex differences in the prevalence of PSP or CBS or that the prevalence of PSP had increased over time, but some evidence to suggest that prevalence may increase with increasing age.

CONCLUSION

Given the paucity of prevalence studies in PSP and CBS, further high-quality prevalence studies are necessary.