Table 4.

Quality Assessment of included cross-sectional studies on

Study	Score	Representativeness of the sample	Sample size	Non-respondents	Ascertainment of the exposure (risk factor)	Comparability of groups/ Adjustment of confounding factors	Assessment of the outcome	Statistical test
Lee et al. 2012	9	*	*	*	**	*	**	*
Rhee et al. 2013	9	*	*	*	**	*	**	*
Jin et al. 2013	8	*	*	*	**	–	**	*
Eom et al. 2014	9	*	*	*	**	*	**	*
Moon et al. 2014	9	*	*	*	**	*	**	*
Chung et al. 2015	9	*	*	*	**	*	**	*
Rotter et al. 2015	7	*	*	*	**	–	*	*
Han et al. 2015	8	*	–	*	**	*	**	*
Lee et al. 2016	9	*	*	*	**	*	**	*
Lee et al. 2017	9	*	*	*	**	*	**	*
Stechemesser et al. 2017	7	*	–	–	**	*	**	*
Park et al. 2018	9	*	*	*	**	*	**	*
Lee et al. 2018	9	*	*	*	**	*	**	*
Shim et al. 2019	9	*	*	*	**	*	**	*
Bulka et al. 2019	10	*	*	*	**	**	**	*
Kaminska et al. 2020	9	*	*	*	**	*	**	*
Wen et al. 2020	7	*	*	–	*	*	**	*
Park et al. 2020	8	*	*	*	**	–	**	*
Lo et al. 2021	10	*	*	*	**	**	**	*
Duc et al. 2021	9	*	*	*	**	*	**	*
Lu et al. 2021	9	*	*	*	**	*	**	*