Table 1.

Cross-Sectional Studies, Risk of Bias Analysis (n = 50).

Assessment	Setting described in detail?	Exposure measured in a valid/reliable way?	Objective, standard criteria used for measurement of the condition?	Confounding factors identified?	Were strategies to deal with confounding factors stated?	Were the outcomes measured in a valid and reliable way?	Was appropriate statistical analysis used?
Yes	39	50	50	47	42	48	50
No	2	0	0	3	1	2	0
Unclear	9	0	0	0	7	0	0