Table 5.

Quality of included studies using the Newcastle–Ottawa Scale (NOS) tool

Study	Selection****	Comparability**	Outcome***	Score
Boven et al. [24]	****	*	***	8
Krennmair et al. [25]	****	*	**	7
Zou et al. [26]	****	*	***	8
Katsoulis et al. [28]	****	*	***	8
Ferrigno et al. [10]	****	**	**	8

Studies that met five or more of the NOS score criteria were considered as good quality