Skip to content Accessibility statement

Reporting of adverse effects in drug trials has only improved slightly in 17 years, new study shows.

News

Posted on Friday 9 July 2021

A new study suggests that better reporting of adverse effects in drug trials would help inform the public of any potential harms.
A picture of pills and a pill bottle
In 2004, major new guidelines on reporting Randomised Controlled Trials (RCTs) were published, with the aim of improving the reporting of adverse effects in trials.

Researchers, including academics from the University of York, analysed systematic reviews of 1,200 Randomised Controlled Trials (RCTs) to assess whether reporting had improved over time.

However, the information the researchers needed to assess what adverse effects were reported (and how they were reported) was only included in less than half of the RCTs they analysed.

Co-author Dr Su Golder from the Department of Health Sciences, said: “Drug trials are conducted to give clinicians information on the benefits and adverse effects of treatments. Our study shows that, disappointingly, there’s only been a slight improvement in reporting the adverse effects in trials over the last 17 years.”

Minor harms

The study argues that many trials focus on the benefits, rather than the adverse effects of the drug being trialled.

There is also a tendency to focus only on those harms that are either common, or defined as serious which cause hospitalisation, disability or death. Yet other seemingly minor harms which may be important to patients - everything from diarrhoea and insomnia to rashes, coughs and muscle aches - may be important to capture, especially since it may stop people taking medication,” Dr Golder added.

Randomised Control Trials authors were also at times selective about which harms they reported, the study went on to say. 

Dr Golder added: “We also need to know if a particular drug affected people differently, for example if it affected females more than males, or if a particular harm increased with age.”

Reliable information

The study concluded that the lack of reporting or selective reporting of adverse effects in published clinical trials can promote a false impression of safety and misinform clinical and policy decisions and that the NHS, policy makers and patients all need reliable information about the benefits and adverse effects of treatments to make good, informed decisions.

‘Time to improve the reporting of harms in randomized controlled trials’ is published in the Journal of Clinical Epidemiology.

 

Research newsletter

Our monthly research newsletter features a curated mix of news, events, and recent discoveries delivered straight to your inbox.

Sign up

Explore more news

News

19 May 2026

More than 100 years after Seebohm Rowntree’s landmark study of poverty and social life in York, researchers are once again using pubs to reassess the city’s social fabric.

News

18 May 2026

Scientists have uncovered how tobacco plants naturally make nicotine, solving a mystery that has puzzled researchers for nearly two centuries.

News

18 May 2026

New research reveals that the 4,000-year-old city of Mohenjo-daro defied the ‘rules’ of history by becoming more equal as it became more successful.

News

12 May 2026

Imagine walking down the high street and feeling a powerful spark of recognition for almost every person you pass.

News

8 May 2026

University of York students contributed more than 90,000 hours of service to the City over the last year, providing a vital economic and social boost to the region.

Read more news