Table 3.

Newcastle–Ottawa Scale (NOS) score for methodological quality assessment of observational studies.

Study	S1	S2	S3	S4	C	E1	E2	E3	Total scale	Quality
Ben-Bassat et al. (33)	*	*	*	–	*	*	*	–	6	Moderate
Glowacki et al. (35)	–	*	*	*	**	*	*	*	8	High
Huggare et al. (44)	*	*	*	*	**	*	*	*	9	High
Korbmacher et al. (37)	–	*	–	–	**	*	–	*	5	Moderate
Kostenko et al. (34)	*	–	–	–	**	*	*	*	6	Moderate
Laskowska et al. (39)	*	*	–	*	**	*	*	*	8	High
Lewandowska et al. (45)	*	*	*	*	**	*	*	*	9	High
Lippold et al. (38)	*	*	*	*	**	*	–	*	8	High
Pecina et al. (43)	*	*	*	*	**	*	*	*	9	High
Sambataro et al. (42)	*	*	*	*	*	*	–	*	8	High
Segatto et al. (40)	*	*	–	*	**	*	*	–	7	High
Sofyanti et al. (36)	*	*	–	–	**	*	–	*	6	Moderate
Uçar et al. (46)	*	*	–	–	**	*	*	*	7	High
Zhang et al. (41)	*	*	–	*	**	*	*	*	8	High