Table 3.

JBI critical appraisal of the included case control studies.

	Study	Lin et al., 2017 [18]	Lin et al., 2017 [16]	Li et al., 2021 [19]	Hou et al., 2022 [17]
Q1	Were the groups comparable other than the presence of disease in cases or the absence of disease in controls?	Yes	Yes	Yes	Yes
Q2	Were cases and controls matched appropriately?	Yes	Yes	Yes	Yes
Q3	Were the same criteria used for identification of cases and controls?	Yes	Yes	Yes	Yes
Q4	Was exposure measured in a standard, valid and reliable way?	Yes	Yes	Yes	Yes
Q5	Was exposure measured in the same way for cases and controls?	Yes	Yes	Yes	Yes
Q6	Were confounding factors identified?	Unsure	Unsure	Unsure	Unsure
Q7	Were strategies to deal with confounding factors stated?	Unsure	Unsure	Unsure	Unsure
Q8	Were outcomes assessed in a standard, valid and reliable way for cases and controls?	Yes	Yes	Yes	Yes
Q9	Was the exposure period of interest long enough to be meaningful?	Yes	Yes	Yes	Yes
Q10	Was appropriate statistical analysis used?	Yes	Yes	Yes	Yes
	Total Score	80%	80%	80%	80%