Table 2.

Risk of bias in prevalence studies.

Studies	Was the sample frame appropriate to address the target population?	Were study participants sampled in an appropriate way?	Was the sample size adequate?	Were the study subjects and the setting described in detail?	Was the data analysis conducted with sufficient coverage of the identified sample?	Were valid methods used for the identification of the condition?	Was the condition measured in a standard, reliable way for all participants	Was there appropriate statistical analysis?	Was the responses rate adequate, and if not, was the low response rate managed appropriately?
Oh et al. (21)	Yes	Yes	No	Yes	Yes	Yes	Yes	Yes	No
Rammohan et al. (14)	Yes	Yes	No	Unclear	Yes	Yes	Yes	Yes	Unclear
Senaratne et al. (22)	Yes	Yes	Unclear	Yes	Yes	Yes	Yes	Yes	Yes
Victor et al. (18)	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Yong et al. (23)	Yes	Yes	No	Yes	Yes	Yes	Yes	Yes	Yes