Will the development of a Core Outcome Set on prevention and treatment of postpartum haemorrhage add value to research or clinical care?

The purpose of Core Outcome Sets (COS) is to allow comparison of different studies and aggregations of findings; this is complicated by studies of small size with a lot of heterogeneity in the number of outcomes reported: 121 trials and 68 outcomes in the case of postpartum haemorrhage (PPH). The idea is that COS will improve the quality of metanalyses by decreasing heterogeneity and increasing number of studies that can be compared from different countries and settings. More complex metanalyses e.g. nested metanalysis* would also be facilitated, thus allowing comparison of large numbers of treatments (Sarri et al BJOG. 2017 124:1514-1523). However, it is essential that there is a common outcome in each study drawn from the COS - and ideally this would be as the primary end point, so a small number of outcomes will be reported in many studies. This article is protected by copyright. All rights reserved.