Table 3.

Risk of bias assessment according to the Newcastle-Ottawa scale for the non-randomized study [9] included in this meta-analysis (Leg.: scores ≥7–9, 4–6, <4 are considered as low, intermediate, and high risk, respectively); ^*= 1 point

Study	Selection				Comparability of cohorts	Outcome			Overall
	Representativeness	Selection of	Ascertainment	Outcome not		Assessment	Adequate follow-up	Adequacy of
	of exposed cohort	nonexposed	of exposure	present at start			length	follow-up
Burger et al. REF	*	*	*	*	*	*		*	7/9