Experts in the United States have found that many researchers fail to follow international guidelines when they are carrying out studies funded by the pharmaceutical industry.

They also fail to protect their independence and ensure that their findings are published, particularly if the results are unfavourable.

It is a worry if a drug company is able to find some way of stopping publication of the results of a study

Dr Michael Wilks, BMA

Doctors said the discovery raised serious questions about the integrity of some studies.

They added that it could also stop patients from volunteering to take part in future trials.

Countrywide survey

Doctors at the Duke Clinical Research Institute surveyed 108 medical colleges across the US.

Researchers were asked if they followed guidelines issued by the International Committee of Medical Journal Editors last year.

These guidelines were drawn up by the editors of more than 500 medical journals across the world and are aimed at ensuring studies are robust and of a high standard.

However, the study, which was funded by the institute, revealed that researchers rarely followed the guidelines when they were carrying out research funded by industry.

Just 1% said they had full access to all of the data from the clinical trial. The same proportion said they were able to decide when and where the results of their studies were published.

The survey also showed that many of the contracts between medical colleges and industry were inadequate.

Dr Kevin Schulman, professor of medicine at Duke University Medical Center, said the results were surprising.

"We didn't expect to find full compliance with the guidelines but we were surprised by the extent to which the agreements entered into by medical schools did not protect the independence of investigators in clinical studies and the integrity of their research."

But he added: "This is the first study to look at compliance with the new ICMJE guidelines so we hope it will offer medical schools a road map for how they might improve their agreements with industry sponsors."

Warning

However, Dr Jeremy Sugarman, director of the Center for the Study of Medical Ethics and Humanities at the university, warned that patients could stop volunteering to take part in clinical trials if researchers failed to strengthen their procedures.

"Patients often participate in clinical trials not only for personal benefit, but also because they believe they are contributing to scientific knowledge as a whole.

"If trial data are not made available to others, this may break an implicit promise to research participants that their contributions will be used in such a way."

Dr Michael Wilks, chairman of the British Medical Association's medical ethics committee, said the findings were worrying.

"It is a worry if a drug company is able to find some way of stopping publication of the results of a study which is not favourable to its product."

But he added: "It is different in the UK. Studies are approved by research ethic committees before they can go ahead and I don't think there would ever be a case where they would allow a study to proceed if there was a chance that the drug company could prevent publication of the findings."

The study is published in the New England Journal of Medicine.