TABLE 2.

Scoring method for review articles.

Grading	5 or 6 out of 6	3 or 4 out of 6	0, 1 or 2 out of 6
Risk of bias	Low	Medium	High
Study quality	Good	Satisfactory	Poor
Number of articles identified (n = 65)	18 (27.7%)	7 (10.8%)	40 (61.5%)

Source: Adapted from Wong WCW, Cheung CSK, Hart GJ. Development of a quality assessment tool for systematic reviews of observational studies (QATSO) of HIV prevalence in men having sex with men and associated risk behaviours. Emerg Themes Epidemiol. 2008;5(1):23. https://doi.org/10.1186/1742-7622-5-23