Table 2. Subgroup analyses based on indication for use from randomised controlled trials: Comparison 1—Magnesium sulphate versus placebo or no treatment.
| Outcome and subgroup | Studies | Participants | Method (I2) | RR (95% CI) | χ2, P value, I2 |
|---|---|---|---|---|---|
| 1.1 Perinatal death | |||||
| 1.1.1 Tocolysis | 2 | 257 | F (NA) | 7.99 (1.00, 63.49) | 4.07, 0.13, 50.8% |
| 1.1.2 Pre-eclampsia | 2 | 9,259 | F (0%) | 1.01 (0.91, 1.13) | |
| 1.1.3 Fetal neuroprotection | 4 | 4,138 | F (0%) | 0.96 (0.80, 1.15) | |
| 1.2 Stillbirth | |||||
| 1.2.1 Tocolysis | 2 | 257 | F (NA) | 5.70 (0.28, 116.87) | 1.45, 0.49, 0% |
| 1.2.2 Pre-eclampsia | 3 | 9,961 | F (8%) | 0.99 (0.87, 1.12) | |
| 1.2.3 Fetal neuroprotection | 4 | 2,122 | F (0%) | 0.85 (0.40, 1.80) | |
| 1.3 Neonatal death | |||||
| 1.3.1 Tocolysis | 4 | 445 | R (61%) | 0.78 (0.11, 5.67) | 0.48, 0.79, 0% |
| 1.3.2 Pre-eclampsia | 2 | 9,259 | R (35%) | 1.03 (0.64, 1.65) | |
| 1.3.3 Fetal neuroprotection | 5 | 3,283 | R (0%) | 0.86 (0.68, 1.08) | |
| 1.4 Death > 28 days, before discharge | |||||
| 1.4.1 Tocolysis | 3 | 412 | F (0%) | 0.76 (0.19, 3.09) | 0.37, 0.83, 0% |
| 1.4.2 Pre-eclampsia | 1 | 9,024 | F (NA) | 1.13 (0.55, 2.31) | |
| 1.4.3 Fetal neuroprotection | 1 | 1,255 | F (NA) | 0.88 (0.44, 1.74) | |
Statistically significant effect estimates in bold. Test for heterogeneity represented by I2 statistic; where I2 > 30%, summary estimates were calculated using random-effects meta-analysis. Result of test subgroup differences represented by χ2 statistic, P value, and I2 statistic.
CI, confidence interval; F, fixed-effects; NA, not applicable; R, random-effects; RR, risk ratio.