Table 5. Assessment of cross-sectional using the modified Newcastle–Ottawa Scale for cross-sectional studies.

Study	Selection				Comparability	Exposure		Total	Interpretation
	Q1	Q2	Q3	Q4	Q5	Q6	Q7
Paoli et al [48]	*	*	*	**	**	**	*	10	Good quality
Temiz et al [41]	*	*	*	**	**	**	*	10	Good quality
Ruan et al [32]	*	*	*	**	**	**	*	10	Good quality
Pan et al [33]	*	*	-	*	-	*	*	7	Good quality
Zhang et al [30]	*	*	-	*	-	*	*	7	Good quality

-: not available.