Table 2.

Evaluation of the quality of the studies analysed and the assessment of the risk of bias using JBI critical appraisal checklist for analytical cross sectional studies

	Starr 2018 [22]	Starr 2019 [23]	Shafi 2017 [24]	Wilson 2006 [29]
Were the criteria for inclusion in the sample clearly defined?	Yes	Yes	Yes	Yes
Were the study subjects and the setting described in detail?	Yes	Yes	Yes	Yes
Was the exposure measured in a valid and reliable way?	Yes	Yes	Yes	Yes
Were objective, standard criteria used for measurement of the condition?	Yes	Yes	Yes	Yes
Were confounding factors identified?	No	No	Yes	Yes
Were strategies to deal with confounding factors stated?	No	No	Yes	Yes
Were outcomes measured in a valid a reliable way?	Yes	Yes	Yes	Yes
Was appropriate statistical analysis used?	Yes	Yes	Yes	Yes