MedicalResearch.com Interview with: Matthias Briel, MD, MSc Basel Institute for Clinical Epidemiology and Biostatistics, University Hospital of Basel, Basel, Switzerland Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario, Canada  MedicalResearch.com: What are the main findings of the study? Dr. Briel: Using a retrospective cohort of 1017 randomized controlled trials (RCTs) based on archived protocols approved by six research ethics committees in Switzerland, Germany, and Canada between 2000 and 2003, we found that 25% of initiated RCTs were discontinued. While discontinuation was common with RCTs involving patients (28%), it was rare in RCTs with healthy volunteers (3%). The most commonly reported reason for RCT discontinuation was poor recruitment (10% of included RCTs). We found that trials with investigator sponsor (versus industry) and those with smaller planned sample sizes were at higher risk of discontinuation due to poor recruitment. Of discontinued RCTs, up to 60% remained unpublished. Trial investigators rarely informed research ethics committees about trial discontinuation and publication. (more…)