Participation in clinical trials improves outcomes in women's health: a systematic review and meta-analysis.

BACKGROUND: Previous reviews examining the effect of participation in trials on outcomes have not consistently shown benefit. Obstetrics and gynaecology is a unique disease area posing challenges for both researchers and patients. OBJECTIVES: To determine whether participation in randomised controlled trials (RCTs), compared with non-participation, has a beneficial effect on women's health. SEARCH STRATEGY: Medline, Embase, the Cochrane Library, and PsycInfo were searched up to December 2015. SELECTION CRITERIA: We selected studies that reported the same clinical outcomes for participants in a women's health RCT and a comparable non-participant cohort. DATA COLLECTION AND ANALYSIS: Data were extracted on quality, characteristics and study results. Outcomes were compared using logistic regression. MAIN RESULTS: There were 21 relevant studies (20 160 women, 4759 outcome events). Trial participants, compared with non-participants, had 25% better odds of improved outcomes on average (OR 0.75; 95% CI 0.64-0.87; I2  = 64.3%). The beneficial effect of participating in a trial was larger in comparisons where: RCTs were of high quality (OR 0.62; 95% CI 0.50-0.76) versus low (OR 0.92; 95% CI 0.74-1.16); and RCT intervention was not available to non-participants (OR 0.57; 95% CI 0.47-0.69) versus when it was (OR 1.13; 95% CI 0.89-1.44). The effect of trial participation was not influenced by effect size within the RCT (P = 0.48), whether funding was received or not (P = 0.13), whether non-participants received any treatment or not (P = 0.49), and the quality of the comparison of RCT participants with non-participants (P = 0.88). CONCLUSIONS: Women participating in RCTs on average experienced better outcomes compared with those outside trials. TWEETABLE ABSTRACT: Participants in obstetric and gynaecology RCTs experience better outcomes compared with non-participants.

Development of composite outcomes for individual patient data (IPD) meta-analysis on the effects of diet and lifestyle in pregnancy: a Delphi survey.

OBJECTIVE: To develop maternal, fetal, and neonatal composite outcomes relevant to the evaluation of diet and lifestyle interventions in pregnancy by individual patient data (IPD) meta-analysis. DESIGN: Delphi survey. SETTING: The International Weight Management in Pregnancy (i-WIP) collaborative network. Sample Twenty-six researchers from the i-WIP collaborative network from 11 countries. METHODS: A two-generational Delphi survey involving members of the i-WIP collaborative network (26 members in 11 countries) was undertaken to prioritise the individual outcomes for their importance in clinical care. The final components of the composite outcomes were identified using pre-specified criteria. MAIN OUTCOME MEASURES: Composite outcomes considered to be important for the evaluation of the effect of diet and lifestyle in pregnancy. RESULTS: Of the 36 maternal outcomes, nine were prioritised and the following were included in the final composite: pre-eclampsia or pregnancy-induced hypertension, gestational diabetes mellitus (GDM), elective or emergency caesarean section, and preterm delivery. Of the 27 fetal and neonatal outcomes, nine were further evaluated, with the final composite consisting of intrauterine death, small for gestational age, large for gestational age, and admission to a neonatal intensive care unit (NICU). CONCLUSIONS: Our work has identified the components of maternal, fetal, and neonatal composite outcomes required for the assessment of diet and lifestyle interventions in pregnancy by IPD meta-analysis.