A systematic review including 3 RCTs (n=3057), 2 cluster-RCTs (n=683 277) and 5 interrupted time series (n=90 575) was abstracted in DARE. Overall, there was a significant reduction in Caesarean section rates in the intervention groups (RR 0.81, 95% CI 0.75 to 0.87; 10 studies). However, significant statistical heterogeneity was found between the studies (I-squared 87.6%, p<0.00001). There was a significant reduction in Caesarean section rates between groups for the following indicators: dystocia (6 studies), repeat Caesarean section (4 studies), foetal distress (3 studies) and maternal indications (1 study). There was no significant difference between study groups for stillbirth rate (1 study), perinatal and neonatal mortality (3 studies), admission to intensive care (5 studies) or perinatal and maternal morbidity (3 studies).
Comment: The quality of evidence is downgraded by review quality (limited reporting of the review process and combing data of studies with different design and quality) and by inconsistency (heterogeneity).