Table 1.

Quality and risk of bias assessment (SIGN)

Study	Type	Overall assessment of the study	Level of evidence
Gonenc [11]	RCT	Low quality	1-
Lohsiriwat [12]	Cohort	High quality	2++
Wisely [13]	Cohort	Acceptable	2+
Roulin [14]	Cohort	Acceptable	2+
Verheijen [15]	Cohort	Acceptable	2+