Table 1.

Levels of evidence and degree of recommendation for the included studies.

	Study Design	Level of Evidence	Degree of Recommendation
Ji et al. [15]	Retrospective cohort	2b	B
Hartemann et al. [17]	Prospective cohort	1b	A
Gadepalli et al. [18]	Retrospective cohort	2b	B
Kandemir et al. [19]	Retrospective cohort	2b	B
Zhang et al. [20]	Retrospective cohort	2b	B
Noor et al. [21]	Retrospective cohort	2b	B
Zubair et al. [22]	Retrospective cohort	2b	B
Richard et al. [23]	Prospective cohort	1b	A