Trends and Variation in Data Quality on the EU Clinical Trials Register: A Cross-Sectional Study

The EU Clinical Trial Register (EUCTR) is a public facing portal containing information on trials of medicinal products conducted in the European Union (EU) and European Economic Area (EEA). Today, the registry holds information on over 30,000 trials. Given its distinct regulatory purpose, and results reporting requirements, the EUCTR should be a valuable open-source hub for trial information. Past work examining the EUCTR has suggested that data quality on the registry may be lacking. Using the full EUCTR public dataset, we examined areas in which national regulators are expected to ensure data quality including the posting of registrations, updating trial completion information, and monitoring results posting in line with EU guidelines. We identified issues across all areas examined with notable research hubs like France, Spain, and The Netherlands lacking consistent and complete data on the registry. These deficiencies complicate the utility of the EUCTR for research, transparency, and accountability efforts.