Risk of Parkinson’s Disease in the Users of Antihypertensive Agents: An Evidence from the Meta-Analysis of Observational Studies

Table 4

Newcastle-Ottawa Scale to assess the quality of case-control studies.

Study	Selection	Comparability	Outcome	Total score	Quality of the study
Becker et al., 2008 [9]				9	High quality
Ritz et al., 2010 [10]				9	High quality
Ton et al., 2007 [11]				7	Medium quality

A study can be awarded a maximum of 4 stars for selection, a maximum of 2 stars for comparability, and a maximum of 3 stars for exposure.