What discontinued trials teach us about trial registration?

Abstract Objective Trial registries were set up to improve transparency, remove duplication, awareness and avoid waste. Many trials never reach the point of patient enrolment due a myriad reasons. The aim this study was investigate reasons for characteristics discontinuation trials. Results A total 163 discontinued identified compared completed Survey designed further explore nature conduct trial. No differences in registered categorised information observed between Most discontinue or participant recruitment issues, often related funding. Substantial changes procedures protocol strategy also commonly cited available 21 28 no obvious could be identified. Our findings highlight underlying problem lack detail, suboptimal recording, dated incomplete reporting within trial registry which hampers sharing learning. To date, important progress has been made by implementation standards requirement registered. review identifies areas where improvements can made.