Quality of the included studies according to the Delphi list 25
| Author | Year of publication | Reference | 1a | 1b | 2 | 3 | 4 | 5 | 6 | 7 | 8 | Total score |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Ahmaidi | 1993 | 26 | Y | NS | Y | Y | N | N | N | Y | NS | 4 |
| Basaran | 2006 | 3 | Y | NS | Y | N | N | N | N | Y | N | 3 |
| Chang | 2008 | 27 | Y | NS | Y | N | N | N | N | Y | NS | 3 |
| Counil | 2003 | 28 | Y | NS | Y | Y | Y | N | N | Y | N | 5 |
| Dean | 1988 | 29 | N | N | N | N | Y | N | N | N | N | 1 |
| Edenbrandt | 1990 | 30 | Y | NS | N | N | N | N | N | Y | NS | 2 |
| Fanelli | 2007 | 31 | Y | N | Y | Y | N | Y | N | Y | Y | 6 |
| Fitch | 1986 | 32 | N | N | Y | N | N | N | N | Y | Y | 3 |
| Graff | 1980 | 33 | N | N | N | N | N | N | N | N | Y | 1 |
| Henriksen | 1983 | 34 | N | N | N | N | N | N | N | Y | Y | 2 |
| Holzer | 1984 | 35 | N | N | Y | N | N | N | N | Y | NS | 2 |
| Huang | 1989 | 36 | N | N | Y | N | N | N | N | N | N | 1 |
| Lima | 2008 | 38 | Y | NS | Y | Y | N | N | N | Y | N | 4 |
| Matsumoto | 1999 | 39 | Y | NS | Y | N | N | N | N | Y | Y | 4 |
| Moreira | 2008 | 40 | Y | Y | Y | Y | N | N | N | Y | Y | 6 |
| Neder | 1999 | 41 | N | N | N | N | N | N | N | Y | Y | 2 |
| Onur | 2010 | 42 | Y | NS | Y | Y | N | N | N | Y | Y | 5 |
| Orenstein | 1985 | 43 | N | N | Y | N | N | N | N | Y | N | 2 |
| King | 1989 | 37 | N | N | N | N | N | N | N | Y | NS | 1 |
| Sidiropoulou | 2007 | 44 | N | N | Y | Y | N | N | N | Y | Y | 4 |
| Silva | 2006 | 45 | Y | NS | Y | Y | N | N | N | Y | Y | 5 |
| Sly | 1972 | 46 | N | N | N | N | N | N | N | N | N | 0 |
| Svenonius | 1983 | 47 | N | N | Y | Y | N | N | N | Y | Y | 4 |
| Varray | 1991 | 48 | N | N | Y | Y | N | N | N | Y | NS | 3 |
| Varray | 1995 | 49 | N | N | N | Y | N | N | N | Y | NS | 2 |
| Veldhoven | 2001 | 2 | Y | NS | Y | Y | N | N | N | Y | N | 4 |
| Wang | 2009 | 50 | Y | NS | Y | N | N | N | N | N | Y | 3 |
| Weisgerber | 2003 | 51 | Y | N | Y | N | N | N | N | Y | N | 3 |
| Wicher | 2010 | 52 | Y | NS | N | Y | N | N | N | Y | N | 3 |
1a, Treatment allocation: randomisation?; 1b, treatment allocation: concealed?; 2, groups similar at baseline?; 3, eligibility criteria specified?; 4, outcome assessor blinded?; 5, care provider blinded?; 6, patient blinded?; 7, point estimates given?; 8, intention-to-treat analysis?; N; no; NS, not stated; Y, yes.