Table 3.

Risk of bias assessment for individual studies using the methodological index for nonrandomized studies (MINORS) (18).

Item	Masieri (1)	Andolfi (13)	Neheman (22)	Garcìa-Aparicio (24)		Tong (25)	Bansal (26)	Tanaka (27)	Rague (30)	Dangle (11)
1. A clearly stated aim	2	2	2	2		2	2	2	2	2
2. Inclusion of consecutive patients	2	2	2	2		2	2	2	2	2
3. Prospective collection of data	0	2	0	0		0	0	0	0	0
4. Endpoints appropriate to the aim of the study	2	2	2	2		2	2	2	2	2
5. Unbiased assessment of the study endpoint	0	0	0	0		0	0	0	0	0
6. Follow-up period appropriate to the aim of the study	1	1	1	0		1	1	1	1	1
7. Loss to follow-up less than 5%	0	0	0	0		2	0	0	0	0
8. Prospective calculation of the study size	0	0	0	0		0	0	0	0	0
9. An adequate control group	2	2	2	2		2	2	2	2	2
10. Contemporary groups	2	2	2	2		2	2	2	2	2
11. Baseline equivalence of groups	1	1	2	2		2	1	2	1	1
12. Adequate statistical analyses	2	2	2	2		2	2	2	2	2
Total score	14	16	15	14		17	14	15	14	14

0 = not reported; 1 = reported but inadequate; 2 = reported and adequate.

Validated “gold standard” cut-off: 19.8.