Abstract
The publication of the epidemiologically and statistically ill-informed article and analysis presented in ‘Rethinking WHO guidance: review of evidence for misoprostol use in the prevention of postpartum haemorrhage’ 1 is troublesome. While various criticisms may be and have been made of the Cochran review 2 there is no excuse for the lack of awareness of the methodologically stringent review and meta-analysis, 3 which clearly demonstrates that methodologically sound studies find a substantial and highly significant benefit in the provision of misoprostol for postpartum haemorrhage prevention. The authors superficially discuss study quality while ignoring the valid implications thereof in their analysis and interpretation. The criteria by which causal associations are made, of which, statistical significance is but one criterion, particularly the existence of at least one or more methodologically sound studies, the consistency of direction across studies, biological plausibility, temporality, etc. are also critical. While simple presentation of sound studies have been presented that permits valid inference, 4 this article criticizes then includes methodologically questionable information and misconstrues the implications of sound studies, to challenge the more accurate and more sophisticated analyses of the evidence which WHO has correctly used for its inclusion of misoprostol in its recommendations.
Competing interests
None declared