Table 3.
Results of quality assessment using Downs and Black checklist.
| First author (ref.) | Study reporting | External validity | Internal validity, bias | Internal validity confounding | Power | Quality score* |
|---|---|---|---|---|---|---|
| Ahsanuddinl (10) | 1,2,3,4,5,6,7,10 | 11,12,13 | 18,19,20 | 21,22,25 | 27 | 18 |
| Alvares (14) | 1,2,3,6,7,10 | 11,12,13 | 17,18,20 | 21,22,23 | 27 | 16 |
| Ay (4) | 1,2,3,6,8,10 | 11,12,13 | 17,18,20 | 21,22,23 | 27 | 16 |
| Bello (7) | 1,2,3,4,5,6,7,10 | 11,12,13 | 18,19,20 | 21,22,25 | 27 | 18 |
| Burkalter (58) | 1,2,3,4,5,6,7,10 | 11,12,13 | 17,18,19,20 | 22,23,25 | -- | 18 |
| Burkhalter (28) | 1,2,3,4,5*,6,10 | 11,12,13 | 17,18,19,20 | 21,22,23,25 | 27 | 20 |
| Burkhalter (29) | 1,2,3,4,5,6,7,9, 10 | 11,12 | 16,17,18,19,20 | 21,22,23,24,25,26 | 27 | 23 |
| Corruble (30) | 1,2,3,4,5*,6,8,9,10 | 11,12,13 | 17,18,19,20, | 21,22, 26 | 27 | 21 |
| Costa-Requena (59) | 1,2,3,6,7,8,10 | 11,12 | 18,20 | 21,22,23,26 | 27 | 16 |
| Cukor (31) | 1, 2, 3, 4, 6, 7, 10 | 11, 12, 13, | 17, 18, 19, 20 | 21, 22, 25, 26 | 27 | 19 |
| Czyzewski (60) | 1,2,3,4,5,6,7,8,10 | 11,12,13 | 17,18,19,20 | 21,22,25 | -- | 18 |
| De Pasquale (16) | 1,2,3,5,6,7,8,9,10 | 11,12,13 | 17,18,20 | 21,22,26 | 27 | 19 |
| De Pasquale (24) | 1,2,3,6,7,8,10 | 11,12,13 | 17,18,20 | 21,22,23,26 | 27 | 18 |
| De Pasquale (32) | 1, 2 ,3,5,6 ,7,8,9,10 | 11, 12, 13, | 17, 18, 20 | 21, 22, 26, | 27 | 19 |
| De Pasquale (61) | 1,2,3,6,7,8,10 | 11,12,13 | 17,18,20 | 21,22,23,26 | 27 | 18 |
| De Pasquale (9) | 1, 2, 3, 4, 6, 8, 9, 10 | 11, 12, 13 | 17, 18, 19, 20 | 21, 22, 26 | 27 | 19 |
| Denhaerynck (33) | 1, 2, 3, 4, 6, 7,9,10 | 11, 12, 13 | 15, 17, 18, 19, 20 | 21, 22, 23,26 | 27 | 21 |
| Famà (62) | 1,2,3,6,7,10 | 11,12,13 | 17,18,19,20 | 21,22,23,26 | 27 | 18 |
| Fructuoso (34) | 1, 2, 3, 4, 5*, 6, 10 | 11, 12, 13 | 17, 18, 19, 20 | 21, 22, 23, 25 | 27 | 20 |
| Gelb (35) | 1,2,3,4,5*,6,7,9,10 | 11,12,13 | 17,18,19,20 | 21,22,23, | 27 | 21 |
| Gentile (36) | 1, 2, 3, 6, 7, 8, 9, 10 | 11, 12, 13 | 17, 18, 19, 20 | 21, 22, 23, 26 | 27 | 20 |
| Gheith (37) | 1,2,3,4,5*,6,8,9,10 | 11,12,13 | 17,18,19,20, | 21,22, 26 | 27 | 21 |
| Goedendorp (38) | 1,2,3,4,6,7,10 | 11,12,13 | 15,17,18,19,20 | 21,22,23 | 27 | 19 |
| Gordon (39) | 1, 2, 3, 4,5,6, 7, 9, 10 | 11, 12, 13 | 17, 18, 19,20 | 21, 22, 26 | 27 | 20 |
| Gross (40) | 1, 2,3,4,5*, 6, 7, 8, 9, 10 | 11, 12, 13 | 16, 17, 18, 19, 20 | 21, 22, 23, 24, 25, 26 | 27 | 26 |
| Hucker (63) | 1,2,3,4,5,6,7,10 | 11,12,13 | 17,18,19,20 | 22,23,25 | -- | 18 |
| Husain (64) | 1,2,3,4,6,7,10 | 11,12,13 | 18,19,20 | 21,22, | 27 | 16 |
| Kofman (41) | 1,2,3,4,5,6,7,8,9,10 | 11,12,13 | 17,18,19,20 | 21,22,23,25,26 | 27 | 24 |
| Kovacs (42) | 1,2,3,6,7,9,19 | 11,12,13 | 15,17,18,19,20 | 21,22,23,25,26 | 27 | 21 |
| Kung (65) | 1,2,3,4,6,10 | 11,12,13 | 18,19,20 | 21,22,25,26 | 27 | 17 |
| Liaveri (66) | 1,2,4,6,7,10 | 11,12,13 | 18,19,20 | 22,25,26 | 27 | 16 |
| Mc Adams (43) | 1,2,3,4,5,6,7,10 | 11,12,13 | 16,17,18,19,20 | 21,22,23,25,26 | 27 | 22 |
| Muller (44) | 1,2,3,5,6,7,9,10 | 11,12,13 | 17,18,19,20 | 21,22,23,24,25,26 | 27 | 22 |
| Neri (67) | 1,2,3,4,6,9,10 | 11,12 | 18,19,20 | 21,22,26 | 27 | 16 |
| Panagopoulou (68) | 1,2,3,6,7,10 | 11,12,13 | 16,17,18,20 | 21,22,25 | 27 | 17 |
| Paterson (45) | 1,2,3,4,5,6,7,8,9,10 | 11,12,13 | 16,17,18,19,20 | 21,22,23,25,26 | 27 | 24 |
| Pistorio (46) | 1, 2, 3,5, 6,7, 8, 10 | 11, 12, 13 | 17, 18, 19, 20 | 21, 22, 25 | 27 | 19 |
| Pistorio (20) | 1,2,3,5,6,7,8,9 | 11,12,13 | 18,19,20 | 22,25 | 27 | 17 |
| Pistorio (21) | 1, 2, 3,5, 8, 10 | 11, 12, 13 | 17, 18, 19, 20 | 21, 22, 25 | 27 | 17 |
| Pourfarziani (47) | 1,2,3,5*,6,7,10 | 11,12,13 | 17,18,19,20 | 21,22,26 | 27 | 19 |
| Prihodova (48) | 1, 2, 3, 5*, 6, 7, 10 | 11, 12, 13 | 17, 18, 19, 20 | 21, 22, 26 | 27 | 19 |
| Raiesifar (49) | 1, 2, 3, 4, 6, 7, 10 | 11, 12, 13 | 15, 17, 18, 19, 20 | 21, 22, 23 | 27 | 19 |
| Reilly-Spong (50) | 1,2,3,4,5*6,7,8,9,10 | 11,12,13 | 16,17,18,19,20 | 21,22,23,25,26 | 27 | 25 |
| Ronai (69) | 1,3,5,6,8,9,10 | 11,12 | 16,18,19 | 22,23,25 | 27 | 16 |
| Shabany (51) | 1, 2, 3, 4, 6, 7, 9, 10 | 11, 12, 13 | 18, 19, 20 | 21, 22, 25, 26 | 27 | 19 |
| Sieverdes (70) | 1,2,3,4,6,7,10 | 11,12,13 | 18,19,20 | 21,22,25 | 27 | 18 |
| Silva (52) | 1,2,3,6,7,9,10 | 11,12,13 | 17,18,19,20 | 21,22,23,24,25,26 | 27 | 21 |
| Srifuengfung (71) | 1,2,3,6,7,8,10 | 11,12 | 16,18,20 | 22,23,26 | 27 | 16 |
| Szeifert (72) | 1,2,3,6,7,10 | 11,12,13 | 17,18,20 | 21,22,23 | 27 | 16 |
| Tamura (73) | 1,3,6,8,10 | 11,12,13 | 18,19,20 | 21,22,25 | 27 | 15 |
| Tavallaii (74) | 1,2,3,6,9,10 | 11,12,13 | 17,18,19,20 | 21,22,23 | 27 | 17 |
| Troen (53) | 1,2,3,4, 5*, 6, 7, 9, 10 | 11, 12, 13 | 14, 15, 16, 17, 18, 19, 20 | 21, 22, 23, 24, 25, 26 | 27 | 27 |
| Van Lint (75) | 1,2,3,4,6,7,10 | 11,12,13 | 17,18,19,20 | 21,22,23,26 | -- | 18 |
| Von Der Lippe (54) | 1, 2, 3,5,6, 7, 9, 10 | 11, 12, 13 | 17, 18, 19, 20 | 21, 22, 26 | 27 | 19 |
| Wang (76) | 1,2,3,4,7,9,10 | 11,12,13 | 18,20 | 23,25,26 | 27 | 16 |
| Wei (55) | 1, 2, 3, 5,6, 7,8, 9, 10 | 11, 12, 13 | 17, 18, 20 | 21, 22, 26 | 27 | 19 |
| Weng (56) | 1,2,3,4,5*,6,8,9,10 | 11,12,13 | 15,17,18,19,20 | 21,22,26 | 27 | 22 |
| Weng (77) | 1,2,3,4,6,7,8,9,10 | 11,12,13 | 18,19,20 | 25,26 | 27 | 18 |
| Xie (78) | 1,2,3,4,5,6,7,10 | 11,12,13 | 18,19,20 | 21,22,25 | 27 | 18 |
| Zelle (57) | 1,2,3,4,5*,6,10 | 11,12,13 | 17,18,19,20 | 21,22,23,25 | 27 | 20 |
| Zhao (79) | 1,2,3,4,5,6,7,10 | 11,12,13 | 18,19,20 | 21,22,25 | 27 | 18 |
| Zhu (80) | 1,3,6,7,8,9,10 | 12,13 | 18,19,20 | 23,25,26 | 27 | 16 |
*Item 5 = 2.