Only a third of clinical trials led by investigators at major US academic centres are published within two years of completion, research shows.

And only 13 percent of the completed trials were reported on ClinicalTrials.gov found the study published in the BMJ.

 The study also revealed marked variation in rates of dissemination of clinical trial results across academic institutions.

For instance there was a more than twofold variation in the average time from study completion to dissemination of results and more than a threefold variation in the rate of dissemination across institutions.

No academic centre published more than 40% of completed clinical trials within two years of completion or reported results for more than 41% of its trials, reported the research team led by Professor Harlan Krumholz from the Yale School of Medicine.

They point out that there is “no effective enforcement mechanism and no repercussions to academic institutions or individual investigators” for failing to report results.

“The lack of timely dissemination of the findings of clinical trials fundamentally impairs the research enterprise, violates the commitment made by investigators to patients and funders, squanders precious time and resources, and threatens to compromise evidence based clinical decision making,” they conclude.