PRISMA statement results | Â | Â | Â | Â | Â | Â | ||
---|---|---|---|---|---|---|---|---|
 |  |  | Yes | Partial | No | |||
Title | 1 | Title | 221 | (93%) | 13 | (5%) | 2 | (0%) |
Abstract | 2 | Structured summary | 82 | (35%) | 147 | (62%) | 7 | (3%) |
Introduction | 3 | Rationale | 233 | (98%) | 3 | (1%) | 0 | (0%) |
Methods | 4 | Objectives | 143 | (60%) | 90 | (38%) | 3 | (1%) |
 | 5 | Protocol and registration | 2 | (1%) | 35 | (15%) | 199 | (84%) |
 | 6 | Eligibility criteria | 209 | (88%) | 27 | (11%) | 0 | (0%) |
 | 7 | Information sources | 235 | (99%) | 1 | (0%) | 0 | (0%) |
 | 8 | Search | 59 | (25%) | 177 | (75%) | 0 | (0%) |
 | 9 | Study selection | 134 | (57%) | 30 | (13%) | 72 | (30%) |
 | 10 | Data collection process | 149 | (63%) | 16 | (7%) | 71 | (30%) |
 | 11 | Data items | 127 | (54%) | 64 | (27%) | 45 | (19%) |
 | 12 | Risk of bias in individual studies | 103 | (43%) | 79 | (33%) | 54 | (23%) |
 | 13 | Summary measures | 235 | (99%) | 0 | (0%) | 1 | (0%) |
 | 14 | Synthesis of results | 234 | (99%) | 2 | (1%) | 0 | (0%) |
 | 15 | Risk of bias across studies | 152 | (64%) | 30 | (13%) | 54 | (23%) |
 | 16 | Additional analyses | 101 | (43%) | 12 | (5%) | 123 | (52%) |
Results | 17 | Study selection | 112 | (47%) | 91 | (38%) | 33 | (14%) |
 | 18 | Study characteristics | 132 | (56%) | 94 | (40%) | 10 | (4%) |
 | 19 | Risk of bias within studies | 76 | (32%) | 84 | (36%) | 76 | (32%) |
 | 20 | Results of individual studies | 162 | (68%) | 36 | (15%) | 39 | (16%) |
 | 21 | Synthesis of results | 235 | (99%) | 1 | (0%) | 0 | (0%) |
 | 22 | Risk of bias across studies | 136 | (57%) | 35 | (15%) | 65 | (27%) |
 | 23 | Additional analyses | 90 | (38%) | 24 | (10%) | 122 | (51%) |
Discussion | 24 | Summary of evidence | 232 | (98%) | 4 | (2%) | 0 | (0%) |
 | 25 | Limitations | 139 | (59%) | 38 | (16%) | 59 | (25%) |
 | 26 | Conclusions | 232 | (98%) | 4 | (2%) | 0 | (0%) |
Funding | 27 | Funding | 114 | (48%) | 0 | (0%) | 122 | (51%) |