Was there a If not there could be potential issues with number of study quality. confounders controlled for that may have an effect on the outcome? ls/are the authors' If not there could be potential issues with conclusions bias. justifiable? Can the study If not there could be potential issues with results be study quality. applicable to the target population? Ca~~-CQDt[QI Question Yes No Comment Does the study ask a specific question? Were the cases If not there could be potential issues with and controls from bias. comparable populations? Was the same If not there could be potential issues with exclusion criteria bias. used for both cases and controls? Were cases well-If not there could be potential issues with defined and bias. different from controls? Were controls well-If not there could be potential issues with defined and bias. different from cases? Were cases well-If not there could be potential issues with defined using study quality. similar methods that are considered one of the best methods to determine disease/ outcome? Was exposure If not there could be potential issues with status measured study quality. using the most appropriate and reliable methods for the exposure of interest? Was there a If not there could be potential issues with