Table 4.
A summary of results for tocolytic treatment versus no treatment for extremely preterm birth outcomes in non-RCTs
| Tocolysis compared to no treatment for women with extremely preterm birth (non-RCTs) | |||||
| Patient or population: Women with extremely preterm birth | |||||
| Intervention: Tocolysis | |||||
| Comparison: no treatment | |||||
| Outcomes | Anticipated absolute effects h(95 % CI) | Relative effect (95 % CI) | № of participants (studies) | Quality of the evidence (GRADE) | |
| Risk with no treatment | Risk with tocolysis | ||||
| Prolongation of pregnancy >7 days | Study population | RR 2.13 (1.12 to 4.06) | 148 (1 non-RCT) | ⨁ VERY LOW a,b | |
| 16 per 100 | 33 per 100 (18 to 63) | ||||
| Prolongation of pregnancy >24 week | Study population | RR 0.91 (0.76 to 1.09) | 101 (1 non-RCT) | ⨁ VERY LOW c | |
| 86 per 100 | 78 per 100 (65 to 94) | ||||
| Prolongation of pregnancy >28 weeks | Study population | RR 0.91 (0.69 to 1.20) | 222 (1 non-RCT) | ⨁ VERY LOW d | |
| 55 per 100 | 50 per 100 (38 to 66) | ||||
| Prolongation of pregnancy >32 weeks | Study population | RR 0.94 (0.76 to 1.17) | 323 (2 non-RCTs) | ⨁ VERY LOW e | |
| 51 per 100 | 48 per 100 (39 to 60) | ||||
| Prolongation of pregnancy >35 weeks | Study population | RR 0.96 (0.75 to 1.23) | 323 (2 non-RCTs) | ⨁ VERY LOW e | |
| 43 per 100 | 41 per 100 (32 to 52) | ||||
| Neonatal survival | Study population | RR 1.12 (0.92 to 1.37) | 222 (1 non-RCT) | ⨁ VERY LOW d | |
| 62 per 100 | 69 per 100 (57 to 85) | ||||
| Perinatal death | Study population | RR 0.73 (0.55 to 0.95) | 370 (2 non-RCT) | ⨁ VERY LOW b,f | |
| 43 per 100 | 31 per 100 (24 to 41) | ||||
| GRADE Working Group grades of evidence | |||||
| High quality: We are very confident that the true effect lies close to that of the estimate of the effect | |||||
| Moderate quality: We are moderately confident in the effect estimate: The true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different | |||||
| Low quality: Our confidence in the effect estimate is limited: The true effect may be substantially different from the estimate of the effect | |||||
| Very low quality: We have very little confidence in the effect estimate: The true effect is likely to be substantially different from the estimate of effect | |||||
| aThe information was from a study with high risk of confounding variables and unclear risk of outcome data reporting | |||||
| bA wide confidence interval without confounding variable adjusted | |||||
| cThe information was from a study with high risk of selective reporting | |||||
| dThe information was from a study with unclear risk of incomplete outcome data | |||||
| eThe information was from two studies with unclear risk of incomplete outcome data in one study and high risk of selective reporting in another study | |||||
| fThis information was from two studies with unclear risk of incomplete outcome data and on study with high risk of cofounding variables and unclear selective reporting | |||||
| gThis information was from a study with unclear risk of selection of participants, measurement of exposure, incomplete data and selective reporting | |||||
CI Confidence interval; RR Risk ratio; OR Odds ratio
hThe risk in the intervention group (and its 95 % confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95 % CI)