Table 1.

Study Design and OCEBM Level of Evidence for the Included Studies.

Authors and years	Study design	OCEBM scale (level of evidence)
Basciani and Intiso, 20062	Prospective cohort	Level III
DeMatteo et al, 20064	Case series	Level IV
Desiato and Risina, 20015	Prospective cohort	Level III
Price et al, 200714	Retrospective cohort	Level IV
Rollnik et al, 200015	Retrospective cohort	Level IV
Duijnisveld et al, 20176	Prospective comparative	Level III
Greenhill et al, 20189	Retrospective cohort	Level IV
Michaud et al, 201413	Retrospective cohort	Level IV
Shin et al, 201416	Case report	Level V
Hierner et al, 200111	Retrospective cohort	Level IV

Note. OCEBM = Oxford Centre for Evidence-Based Medicine.