Time to publication for publicly funded clinical trials in Australia: an observational study

To examine the length of time between receiving funding and publishing the protocol and main paper for randomised controlled trials.

An observational study using survival analysis.

Publicly funded health and medical research in Australia.

Randomised controlled trials funded by the National Health and Medical Research Council of Australia between 2008 and 2010.

Time from funding to the protocol paper and main results paper. Multiple variable survival models examining whether study characteristics predicted publication times.

We found 77 studies with a total funding of $A59 million. The median time to publication of the protocol paper was 6.4 years after funding (95% CI 4.1 to 8.1). The proportion with a published protocol paper 8 years after funding was 0.61 (95% CI 0.48 to 0.74). The median time to publication of the main results paper was 7.1 years after funding (95% CI 6.3 to 7.6). The proportion with a published main results paper 8 years after funding was 0.72 (95% CI 0.56 to 0.87). The HRs for how study characteristics might influence timing were generally close to one with narrow CIs, the notable exception was that a longer study length lengthened the time to the main paper (HR=0.62 per extra study year, 95% CI 0.43 to 0.89).

Despite the widespread registration of clinical trials, there remain serious concerns of trial results not being published or being published with a long delay. We have found that these same concerns apply to protocol papers, which should be publishable soon after funding. Funding agencies could set a target of publishing the protocol paper within 18 months of funding.