Table 3.

Risk of bias assessment for randomized controlled trials (adapting cochrane collaboration criteria), and cohort studies (adapting MINORS scale)

Author, year	Cochrane collaboration tool
	Adequate sequence generation	Allocation concealment	Blinding	Incomplete outcome data	Selective reporting	Other source of bias
Risk of bias assessment for cohort studies (adapting MINORS scale)
Bickell et al. [13]	Probably	Probably	Unlikely	No	Unlikely	No
Dutton et al. [26]	No	Unlikely	Unlikely	No	Probably	No
Morrison et al. [27]	Unlikely	Probably	No	No	Probably	No
Schreiber et al. [28]	No	No	Unlikely	Yes	No	Probably
Carrick et al. [29]	No	No	Unlikely	Unlikely	Probably	Probably

Author, Year	A Clearly Stated aim	Inclusion of consecutive patients	Prospective collection of data	Endpoints appropriate to the aim of the study	Unbiased assessment of the study endpoint	Follow-up period appropriate to the aim of the study	Loss to follow up less than 5%	Prospective calculation of the study size	An adequate control group	Contemporary groups	Baseline equivalence of groups	Adequate statistical analyses	Total
Risk of bias assessment for cohort studies (adapting MINORS scale)
MINORS items
Talving et al. [32]	2	2	0	1	1	1	2	1	N/A	N/A	N/A	N/A	10/16
Ley et al. [33]	2	0	0	1	1	1	1	1	N/A	N/A	N/A	N/A	7/16
Kasotakis et al. [30]	2	0	2	2	1	2	2	1	N/A	N/A	N/A	N/A	12/16
Geeraedts et al. [34]	2	0	0	2	1	1	2	1	N/A	N/A	N/A	N/A	9/12
Comparative cohort study
Brown et al. [31]	1	0	2	2	1	2	0	1	1	2	1	1	14/24

N/A not applicable

*The items are scored as following: 0 = not reported, 1 = reported but not adequate, 2 = reported and adequate