All of us had seen instances of where cash interests had been put before patients

Dr Richard Horton, The Lancet

The publications include the Lancet, the Journal of the American Medical Association, the Canadian Medical Association Journal, and the Dutch Journal of Medicine.

Dr Richard Horton, the editor of the Lancet, one of the UK's top journals, said all the editors had seen examples of trials where the best interests of patients had been pushed aside by the interests of the drug companies.

In one case he cited, patients died after a potentially fatal side effect was allegedly discounted by the study authors.

However, the Association of the British Pharmaceutical Industry said that the profession in the UK had high ethical standards, and said it too supported an independent approach.

Marketing drugs

Dr Horton said new drugs had in some cases been manipulated and hyped out of proportion by the companies.

Nine out of 10 reviewers say the papers they receive have been hyped in favour of the drugs and half have to be rejected. Others need to be substantially rewritten before they can be published.

"All of us who signed this had seen instances of where cash interests had been put before patients.

"There are examples of exaggerated benefits and suppressing and avoiding the adverse effects of drugs."

Dr Horton said that it was recognised that clinical trials were expensive - the average cost of bringing a new drug to the market in the USA is about $500m - but he said it was important that drug companies investing in trials should take a back seat.

"We would not have any medical advances if it was not for pharmaceutical companies investing in drugs, but at the same time they have to put the interests of patients first."

The International Committee of Medical Journal Editors (ICMJE) has now strengthened its guidelines to restrict the publication of those studies where they feel the objectivity is compromised.

Obscure results

"We will not review or publish articles based on studies that are conducted under conditions that allow the sponsor to have sole control of the data or to withhold publication."

"Well-done trials, published in high-profile journals, may be used to market drugs and medical devices, potentially resulting in substantial financial gain for the sponsor.

"But powerful tools must be used carefully."

They say that without these guidelines some trial sponsors might promote or obscure trial results simply because of how they reflect on their products.

And they call on researchers to follow ICMJE requirements on publication ethics to guide the negotiation of research contracts and ensure independent research.

"By enforcing adherence to these revised requirements, we can as editors assure our readers that the authors of an article have had a meaningful and truly independent role in the study that bears their names.

"The authors can then stand behind the published results and so can we."

Medical advances

The British Medical Journal (BMJ) also said it would now require authors to disclose details of their own and the sponsor's role in a study.

Dr Richard Smith, BMJ Editor said: "This initiative should not be seen as an attack on the pharmaceutical industry.

"Many companies have high ethical standards and will see no problem in complying with the new policies. Other groups, including hospitals and governments, may often be keen to control publication especially if results appear to contradict current policy."

A spokesman for the Association of the British Pharmaceutical Industry told BBC News Online: "The ABPI supports the fact that clinical investigations should be independent.

"We believe that the UK pharmaceutical industry supports that."