A systematic review of primary outcomes and outcome measure reporting in randomized trials evaluating treatments for pre-eclampsia

Background: An evaluation of outcome reporting is required to develop a core outcome set. Objectives: To assess primary outcomes and outcome measure reporting in pre-eclampsia trials. Search strategy: Five online databases were searched from inception to January 2016 using terms including “preeclampsia” and “randomized controlled trial”. Selection criteria: Randomized controlled trials evaluating treatments for pre-eclampsia published in any language were included. Data collection and analysis: Primary outcomes and data on outcome measure reporting were systematically extracted and categorized. Main results: Overall, 79 randomized trials including data from 31 615 women were included. Of those, 38 (48%) reported 35 different primary outcomes; 28 were maternal outcomes and seven were fetal/neonatal outcomes. Three randomized trials reported composite outcomes, incorporating between six and nine outcome components. The method of definition or measurement was infrequently or poorly reported. Even when outcomes were consistent across trials, different methods of definition or measurement were frequently described. Conclusions: In randomized trials evaluating interventions for pre-eclampsia, critical information related to the primary outcome, including definition and measurement, is regularly omitted. Developing a core outcome set for pre-eclampsia trials would help to inform primary outcome selection and outcome measure reporting.