A significant proportion of respiratory clinical trials are registered after the trial has started despite a long-standing policy on mandatory prospective trial registration, a new study shows.
The study published in ERJ Express reviewed all of the randomised trials published in 10 major respiratory journals from 2010–2018 and found that more than half had problems with their registration, mainly retrospective registration.
Overall, 47.7% of trials were prospectively registered, and 42.2% were regarded as retrospectively registered. A total of 10.2% of trials were not registered.
The study, led by Nelli Suntila from the Scottish Centre for Respiratory Research at the University of Dundee, was the first to look at adherence to the policy introduced by the International Committee of Medical Journal Editors within respiratory medicine.
Commercially funded trials were more often registered prospectively than academically funded studies, which the authors suggest may reflect stricter regulation imposed on studies with commercial interest.
Studies from certain countries including Spain, South America, Italy and China, and single-centre studies in general, were more likely to be registered inappropriately, which may by explained by variation in regional registration policies and the availability of resources for project management, the authors suggest.
“Registration before the trial starts has been part of the regulations for trial conduct since 2005 and so we were surprised that 13 years later we were still seeing incorrectly registered trials,” one of the authors James Chalmers, Professor of Respiratory Research at the University of Dundee told the limbic.
He points out that there have been big improvements, with the relatively common practice of publishing non-registered trials in 2010 being virtually eliminated by 2018, but says the challenge now is to encourage compliance with prospective registration among investigators and editors.
“We now need to raise awareness among investigators of trial registration requirements to have the same effect in eliminating retrospective registration of trials,” he said.
He thinks that most retrospective registration may be inadvertent and is primarily a problem of lack of awareness, and notes that this is not just a problem in respiratory medicine as similar findings have been seen in other areas such as cardiology, for example.
“We felt is was more often error on the part of investigators rather than a deliberate decision not to register trials.
“Nevertheless trial registration is required for very good reason – to ensure trials are accurately reported and to reduce research waste – and so we think it is very important to highlight this issue and push for 100% prospective registration of trials in future,” he said.
Professor Chalmers says there is a responsibility on journals to adequately check registration status at the time of submission, and that a number of journals, such as the European Respiratory Journal, have strengthened their processes as a result of work such as this to end publication of retrospectively registered trials.
He believes that to improve compliance trial registration needs to be embedded in the process of setting up studies.
In a paper published in the BMJ in March this year, Australian researchers led by Kylie Hunter from the University of Sydney suggested one potential solution is to incorporate registration into the ethics approval process.
Professor Chalmers agrees: “I think if you could not get ethics approval (or R&D approval in the UK) without the trial registration then the compliance would be greatly improved.”
