Table 1.

Bias risk assessment on the studies included in the meta-analysis using the methodological index for non-randomized studies (Minors) criteria (30).

References	Study population	(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	Score
(37)	48	2	2	2	2	2	2	2	0	14
(38)	24	2	2	2	2	2	1	1	0	12
(39)	102	2	2	2	2	2	1	1	0	12
(40)	249	2	2	2	2	2	1	1	0	12
(41)	99	2	2	2	2	2	2	2	0	14
(42)	203	2	2	2	2	2	2	2	0	14
(43)	113	2	2	2	2	2	1	2	0	13
(44)	54	2	2	2	2	2	1	1	0	12
(45)	179	2	2	2	2	2	2	1	0	13
(46)	109	2	2	2	2	2	2	2	0	14
(47)	85	2	2	2	2	2	2	2	0	14
(34)	68	2	2	2	2	2	2	2	0	14
(22)	1591	2	2	2	2	2	2	2	0	14
(48)	1,096	2	2	2	2	2	1	1	0	12
(49)	41	2	2	2	2	2	1	1	0	12
(50)	54	2	2	2	2	2	2	2	0	14
(51)	548	2	2	2	2	2	1	2	0	13
(52)	137	2	2	2	2	2	2	2	0	14
(53)	214	2	2	2	2	2	1	1	0	12
(54)	452	2	2	2	2	2	1	1	0	12
(55)	85	2	2	2	2	2	1	1	0	12
(56)	135	2	2	2	2	2	1	1	0	12
(57)	138	2	2	2	2	2	1	1	0	12
(58)	125	2	2	2	2	2	2	2	0	12
(59)	1,012	2	2	2	2	2	1	2	0	13
(60)	80	2	2	2	2	2	2	2	0	14
(61)	79	2	2	2	2	2	1	1	0	12
(62)	90	2	2	2	2	2	2	2	0	14
(63)	149	2	2	2	2	2	2	2	0	14
(64)	18	2	2	2	2	2	2	2	0	14
(65)	140	2	2	2	2	2	1	1	0	12

(1) A clearly stated aim; (2) Inclusion of consecutive patients; (3) Prospective collection of data; (4) Endpoints appropriate to the aim of the study; (5) Unbiased assessment of the study endpoint; (6) Follow-up period appropriate to the aim of the study; (7) Loss to follow-up less than 5%; (8) Prospective calculation of the study size. The items are scored 0 (not reported), 1 (reported but inadequate), or 2 (reported and adequate). The global ideal score being 16 for non-comparative studies.