Supplementary Table 2.

Quality assessment of cross-sectional studies based on the Joanna Briggs Institute critical appraisal checklist

Studies	Q1	Q2	Q3	Q4	Q5	Q6	Q7	Q8	Score
Proudfoot A.T.[9]	Yes	Yes	Yes	Yes	No	No	Yes	Yes	6/8
Delirrad M.[29]	Yes	Yes	No	Yes	No	No	Yes	Yes	5/8
Kavousi-Gharbi S.[4]	Yes	Yes	Yes	Yes	No	No	Yes	Yes	6/8

Q1. Were the criteria for inclusion in the sample clearly defined?; Q2. Were the study subjects and the setting described in detail?; Q3. Was the exposure measured in a valid and reliable way?; Q4. Were objective, standard criteria used for measurement of the condition?; Q5. Were confounding factors identified?; Q6. Were strategies to deal with confounding factors stated?; Q7. Were the outcomes measured in a valid and reliable way?; Q8. Was appropriate statistical analysis used?