Table 2 A summary of effect size for tocolytic treatment versus placebo for extremely preterm birth outcomes in RCTs
Tocolysis compared to placebo in women with extremely preterm birth (RCTs) | |||||
Patient or population: Women with extremely preterm birth | |||||
Intervention: Tocolysis (atosiban and ritodrine) | |||||
Comparison: Placebo | |||||
Outcomes | Anticipated absolute effectsf (95 % CI) | Relative effect (95 % CI) | № of participants (studies) | Quality of the evidence (GRADE) | |
Risk with placebo | Risk with tocolysis | ||||
Prolongation of pregnancy >24 h | Study population | RR 1.15 (0.81 to 1.63) | 77 (1 RCT) | ⨁⨁⨁ MODERATE a | |
59 per 100 | 68 per 100 (476 to 959) | ||||
Prolongation of pregnancy >48 h | Study population | RR 1.40 (0.83 to 1.31) | 117 (2 RCTs) | ⨁ VERY LOW a,b | |
69 per 100 | 96 per 100 (57 to 90) | ||||
Prolongation of pregnancy >7 days | Study population | RR 1.05 (0.75 to 1.48) | 117 (2 RCTs) | ⨁ VERY LOW a,b | |
65 per 100 | 68 per 100 (49 to 96) | ||||
Perinatal death | Study population | RR 2.22 (0.26 to 19.24) | 265 (2 RCTs) | ⨁ VERY LOW c,d,e | |
17 per 100 | 37 per 100 (4 to 100) | ||||
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 | |||||
aTotal number of cases less than 300 | |||||
bAllocation concealment not performed | |||||
cOne study with unclear randomization and one study without allocation concealment | |||||
dLarge heterogeneity (>60 %) | |||||
eSmall sample size (<300) and wide confidence interval | |||||