Over 40% of clinical trials of drugs currently being examined as possible treatments for COVID-19 have not made their results public, leaving important evidence gaps for the safety of drugs being repurposed for coronavirus patients, a study published today shows.
A team of researchers found that out of 3,754 completed trials involving 19 different drugs, 1,516 trials have made their results public neither on trial registries nor in the academic literature.
According to the study's authors:
“There is an important evidence gap for the safety of drugs being repurposed for COVID-19. This uncertainty could cause a large burden of additional morbidity and mortality during the pandemic. We recommend caution in experimental drug use for non-severe disease and urge clinical trial sponsors to report missing results retrospectively.”
“If clinical decisions are based on incomplete evidence, this can result in avoidable morbidity and mortality if unsafe drugs or ineffective treatments are given on a large scale. Sponsors and researchers alike also carry an ethical responsibility towards clinical trial participants, who consent to participate in research in order to contribute to scientific understanding and improved clinical practice, to make results publicly available. Clinical trial results that are not made available publicly do not fulfil this expectation, betraying the trust of participants who may have given up time and health for the benefit of science. Missing evidence also impacts the direction of future research, which is informed by the existing available body of literature.”
“Overall, our findings reveal a significant evidence gap for the safety of drugs being repurposed for COVID-19. This uncertainty could cause a large burden of extra morbidity in the global pandemic. We recommend caution in experimental drug use for non-severe disease and urge trial sponsors to report missing results retrospectively. Medicine during the COVID-19 pandemic cannot be evidence-based if a large proportion of the evidence is missing.”
Till Bruckner, founder of TranspariMED, said:
“This study highlights the large gaps in medical evidence left by widespread failures to report the results of clinical trials. This problem has been exhaustively documented since the 1980s, but regulators worldwide – with the laudable exception of Denmark – are still refusing to impose fines. "
"Failing to report clinical trial results is not a victimless crime. It’s high time for decision-makers to wake up to the immense human and financial costs of medical research waste and finally put an end to impunity in the sector.”
The study, published today as a pre-print, only included trials listed on the American trial registry ClinicalTrials.gov. While the authors’ literature search followed a clear protocol, past experience shows that such searches can miss some relevant publications. Nonetheless, the study’s findings are broadly consistent with the existing literature on research waste and publication bias, which suggests that around half of all clinical trial results are never made public.
To find out more about how hidden medical evidence harms patients, taxpayers and public health, see past TranspariMED studies and reports.