Table 5.

Quality Assessment of included case–control studies on

Study	Score	Adequacy of case definition	Representativeness of the cases	Selection of controls	Definition of controls	Comparability of cases and controls on the basis of the design or analysis	Ascertainment of exposure	Same method of ascertainment for cases and controls	Non-response rate
Arredondo 2011	8	*	*	*	*	*	*	*	*
Tavakoli-Hoseini,2014	7	*	*	*	*	*	*	*	–
Ghamarchehreh,2016	8	*	*	*	*	*	*	*	*
El Sayed,2017	8	*	*	*	*	*	*	*	*
Guo,2019	7	*	*	*	*	*	*	*	–
Fang,2019	8	*	*	*	*	*	*	*	*
Chen,2020	8	*	*	*	*	*	*	*	*