Table 1 Description of the 2827 included study results and their 455 meta-analyses
Total | Journals with JIF | |||
|---|---|---|---|---|
Study results (N = 2827) | Meta-analyses (N = 455) | Study results (N = 2459) | Meta-analyses (N = 446) | |
Quality of evidence | ||||
High, N (%) | 652 (23.1) | 87 (19.1) | 607 (24.7) | 86 (19.3) |
Moderate, N (%) | 2175 (76.9) | 368 (80.9) | 1852 (75.3) | 360 (80.7) |
Open access | ||||
Yes, N (%) | 239 (8.5) | NA | 190 (7.7) | NA |
Size of meta-analysis | ||||
Ten or more studies, N (%) | 1545 (54.7) | 119 (26.2) | 1330 (54.1) | 118 (26.5) |
Pooling method | ||||
Fixed effects model, N (%) | 1003 (35.5) | 188 (41.3) | 864 (35.1) | 186 (41.7) |
Random effects model, N (%) | 1824 (64.5) | 267 (58.7) | 1595 (64.9) | 260 (58.3) |
Study weight (in %) | ||||
Median (1. to 3. Quartile) | 7.1 (2.8 to 16.6) | NA | 7.4 (2.9 to 16.8) | NA |
Range | < 0.05 to < 50 | NA | < 0.05 to < 50 | NA |
Risk of bias | ||||
Median (1. to 3. Quartile) | 0.21 (0.12 to 0.36) | NA | 0.21 (0.08 to 0.36) | NA |
Range | 0 to 1 | NA | 0 to 0.86 | NA |
Missing, N | 11 | - | ||
Measure of effect | ||||
RR, N (%) | 1375 (54.6) | NA | 1174 (47.7) | NA |
OR, N (%) | 403 (10.9) | NA | 363 (14.8) | NA |
HR, N (%) | 108 (0.5) | NA | 106 (4.3) | NA |
Mean difference, N (%) | 941 (34.0) | NA | 816 (33.2) | NA |
Relative deviationa | ||||
Median (1. to 3. Quartile) | 0.79 (0.33 to 1.41) | NA | 0.77 (0.33 to 1.41) | NA |
Range | < 0.01 to 11.6 | < 0.01 to 11.6 | ||