European trial registry shows under half of studies missing timely results, analysis says

A new analysis of a major European clinical trial database found that fewer than half of the studies reported results within the legally required timeframe, and only 42% provided complete data.

The researchers noted that the registration information itself was of high quality, with more than 99% of the expected data fields present for the 234 trials that were due to disclose results.

They argued that overall compliance with reporting obligations remains weak and that regulatory oversight is insufficient, saying EU and member‑state regulators have not delivered the promised high level of transparency.

The findings were posted as a preprint on medRxiv, underscoring calls for stronger enforcement of reporting rules.