Study design
This study was designed as a nationwide cohort study and included all multicentre RCTs carried out within the Dutch Consortium for Women’s Health Research, embedded within the professional society, i.e. Dutch Society of Obstetrics and Gynaecology (NVOG)(11). The Dutch Consortium for Women’s Health Research facilitated studies in obstetrics, gynaecology and reproductive medicine.
Within the consortium, participating clinical centres are both academic and non-academic hospitals. RCTs conducted within the Consortium are supported by a clinical trial centre (https://zorgevaluatienederland.nl/), a multidisciplinary trial bureau with methodologists, data managers, contract managers and trial managers. The trial centre staff supports research groups by advising on the budget, logistics, methods, and ethics approval, developing electronic case record forms, performing contract management and monitoring, creating the interim reports for the data safety and monitoring board and providing advice on the statistical analyses. We constructed the manuscript according to the STROBE guideline(12).