Close to half of trials unreported

An online tool has estimated that 45 per cent of clinical trials registered since 2006 have not had results published.

A preprint paper in the online journal F1000 Research reported that 45 per cent of 25,927 eligible trials registered since January 2006 have not had results published. The figure, reported on 3 November prior to peer-review, is similar to results reported by manual methods, said the paper’s authors—Anna Powell-Smith and Ben Goldacre of the University of Oxford in the UK.

The TrialsTracker tool scrapes trial registration data from the clinicaltrials.gov registry and checks it against results data from the same registry and from the research paper repository PubMed. It then publishes the results online, enabling the transparency of different clinical trial sponsors—usually pharmaceutical companies—to be compared.