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Comparing and combining evidence of treatment effects in randomized and nonrandomized studies on the use of misoprostol to prevent postpartum hemorrhage
Author(s) -
Morfaw Frederick,
Miregwa Bernard,
Bi Ayaba,
Mbuagbaw Lawrence,
Anderson Laura N.,
Thabane Lehana
Publication year - 2021
Publication title -
journal of evidence‐based medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.885
H-Index - 22
ISSN - 1756-5391
DOI - 10.1111/jebm.12440
Subject(s) - misoprostol , medicine , randomized controlled trial , confidence interval , odds ratio , meta analysis , placebo , medline , relative risk , obstetrics , pregnancy , abortion , alternative medicine , genetics , pathology , political science , law , biology
Objective Postpartum hemorrhage (PPH) is a preventable condition and the main cause of maternal death worldwide. Evidence on the effectiveness of misoprostol in the prevention of PPH has been generated from both randomized controlled trials (RCTs) and nonrandomized studies (NRS). This study aimed to compare the results of RCTs and NRS, and to compare Classical and Bayesian approaches of combining the results of RCTs and NRS on the use of misoprostol versus placebo in the prevention of PPH. Methods We searched MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials for appropriate studies. We pooled estimates of effects from RCTs and NRS seperately, using random‐effects models, then merged them using classical and Bayesian random effects meta‐analysis. Results A total of 34 studies (20 RCTs and 14 NRS) involving 74 204 participants were identified. The summary odds ratio (OR) from RCTs for the use of misoprostol in the prevention of PPH was 0.69 (95% confidence interval [CI]: 0.59 to 0.80). The summary OR from NRS was 0.46 (95% CI: 0.36 to 0.63). Classical and Bayesian approaches of combining the two study designs both showed benefit of misoprostol in preventing PPH, with similar effects. Conclusions Both RCTs and NRS show comparable significant benefit for the use of misoprostol in the prevention of PPH.