Table 1 Basic characteristics of included systematic reviews on adverse events
Basic characteristics | No. of systematic reviews (N = 640) |
|---|---|
Year | |
2008–2011 | 184 (28.75%) |
2015–2020 | 456 (71.25%) |
Region of corresponding author | |
Africa | 15 (2.34%) |
America (North and South) | 193 (30.16%) |
Asia | 193 (30.16%) |
European | 219 (34.22%) |
Oceania | 20 (3.13%) |
Intervention | |
Drug | 483 (75.47%) |
Surgery or device | 108 (16.88%) |
Others (e.g., complementary medicine) | 49 (7.66%) |
Type of meta-analysis | |
Pairwise meta-analysis | 585 (91.41%) |
Network meta-analysis | 17 (2.66%) |
Both pairwise and network meta-analyses | 32 (5.0%) |
Association | 2 (0.31%) |
Individual participant data | 4 (0.63%) |
Protocol | |
Yes | 166 (25.94%) |
No | 474 (74.06%) |
Type of study for meta-analysis | |
Randomized controlled trial (RCT) | 460 (71.88%) |
Non-randomized study of intervention (NRSI) | 89 (13.91%) |
Both RCT and NRSI | 87 (13.59%) |
Not reported | 4 (0.63%) |
Effect estimator | |
Odds ratio, including Peto’s OR | 266 (41.56%) |
Risk ratio or relative risk | 316 (49.38%) |
Hazard ratio | 9 (1.41%) |
Risk difference | 15 (2.34%) |
Others (e.g., mixed use, Chi2, coef.) | 34 (5.31%) |
Systematic review with zero-events studies in meta-analysis | |
Yes | 406 (63.45%) |
No | 88 (13.75%) |
No data available for judgment | 146 (22.80%) |
Power analysis | |
Yes | 16 (2.50%) |
No | 624 (97.5%) |