Table 4.
Assessment of bias across all studies
| Article4 | Selection bias | Performance bias | Detection bias | Attrition bias | Reporting bias | Overall bias |
|---|---|---|---|---|---|---|
| Anstiss and Davies (35) | High | Unclear | Unclear | High | High | High |
| Bobier et al. (36) | Low | Unclear | Unclear | Low | Low | Unclear |
| Bradley et al. (37) | Low | Low | Low | Unclear | High | Unclear |
| Burckhardt et al. (38) | Low | Low | Low | Low | Low | Low |
| Calear et al. (39) | Low | Unclear | Unclear | Low | Low | Unclear |
| Carrasco (40). | Low | Low | Low | Low | Low | Low |
| Chapman et al. (41) | Low | Low | Low | Low | Low | Low |
| Chen et al. (42) | Low | Low | Low | Low | Low | Low |
| Clarke et al. (43) | Low | Low | Unclear | Low | Low | Low |
| de Voogd et al (44) | High | Low | Low | High | High | High |
| Gerrits et al. (45) | Low | Low | Low | High | Low | High |
| Gladstone et al. (46) | Low | Low | High | Low | Low | High |
| Hetrick et al. (47) | Low | Low | High | High | Low | High |
| Horgan et al. (48) | Low | Low | High | High | High | High |
| Ip et al. (49) | Low | Low | Low | High | Low | High |
| King et al. (50) | Low | Low | Unclear | Low | High | High |
| Kramer et al. (51) | High | Low | High | High | Low | High |
| Levin et al. (52) | High | Low | High | Low | Low | High |
| Lillevoll et al. (53) | Unclear | Low | Unclear | High | Low | High |
| Manicavasagar et al. (54) | Unclear | Low | Unclear | High | Low | High |
| Melnyk et al. (55) | High | Low | Unclear | Unclear | High | High |
| Merry et al. (56) | Low | Low | High | Low | Low | High |
| Neil et al. (57) | Unclear | Low | Unclear | Unclear | High | High |
| Pinto et al. (58) | Low | Low | High | High | Low | High |
| Reid et al. (59) | Low | Low | High | Low | Low | High |
| Rice et al. (60) | Low | Low | Low | Low | Low | Low |
| Rickhi et al. (61) | Low | Low | High | Low | High | High |
| Robinson et al. (62) | High | Low | Low | High | High | High |
| Robinson et al. (63) | High | Low | Low | High | High | High |
| Saulsberry et al. (64) | Low | Low | High | High | Low | High |
| Sekizaki et al. (65) | High | Low | High | Low | Low | High |
| Smith et al. (66) | Unclear | Low | Unclear | Low | Low | Unclear |
| Spence et al. (67) | Low | Low | High | Low | Low | High |
| Stasiak et al. (68) | Low | Low | Low | Low | Low | Low |
| Taylor-Rodgers & Batterham (69) | Low | Low | High | Low | Low | High |
| van der Zanden et al. (70) | Unclear | Low | Unclear | Low | Low | Unclear |
| Wade et al. (71) | Low | Low | High | Low | Low | High |
| Whiteside et al. (72) | High | Low | High | Low | Low | High |
| Whittaker et al. (73) | Low | Low | Low | Low | Low | Low |
| Whittaker et al. (74) | Low | Low | Low | Low | Low | Low |
| Wojtowicz et al. (75) | Low | Low | High | Unclear | High | High |