The global pharmaceutical industry is accused today of manipulating scientific research to boost its commercial interests at the expense of patients.

The global pharmaceutical industry is accused today of manipulating scientific research to boost its commercial interests at the expense of patients.

In a joint statement, a dozen of the world's leading medical journals have agreed to ban publication of research that they do not consider to be independent. They say drug companies who pay for research increasingly control the design of studies, how results are analysed and whether findings are published. Findings that are not in their interests are censored.

Thus, a study of a drug for HIV submitted to the Journal of the American Medical Association last November was manipulated when the study's sponsors refused to provide all the data to the scientists running the trial. In another case, Boots tried to suppress a study four years ago that failed to show its product levothyroxine, prescribed for thyroid problems, was superior to its rivals.

"The use of clinical trials primarily for marketing, in our view makes a mockery of clinical investigation ... corporate sponsors have been able to dictate the terms of participation in the trial, terms that are not always in the best interests of academic investigators, the study participants or the advancement of science generally, " the joint statement from the International Committee of Medical Journal Editors says.

Concern over drug companies' influence on medical research has been growing for years. The rising cost of developing and testing new drugs has led the companies to control research data to protect their investment.

But the editors of the journals, which include the British Medical Journal and The Lancet, say the process has gone too far.

Richard Horton, editor of the latter, said : "We are all completely fed up with being manipulated by the industry. Nine out of 10 research papers about new drugs submitted to The Lancet are so hyped in favour of the drug that we can't publish them without revisions. There may be a design flaw or the adverse effects have been underplayed or the results over-interpreted. Research papers are now used more as a marketing exercise than as scientific reports."

Often scientists were happy to rewrite their papers when flaws were exposed in them, Dr Horton noted. "It looks to us that they come under pressure from their sponsors and that they welcome the reality check we provide."

Patients in the trials were hoodwinked into thinking they were advancing medical science when actually they were being used in a marketing exercise. "That is a subversion of patient consent," he said.

The withdrawal of state funding for medical research had accentuated the problem. "But as soon as you abandon medical research and leave it to the drug industry, you are playing Russian roulette," he added.

Richard Smith, editor of the British Medical Journal, said many drug companies had high ethical standards. "Other groups, including hospitals and governments, may often be keen to control publication, especially if results appear to contradict current policy."

Scientists submitting research papers to the journals will in future be asked to sign a declaration that they accept full responsibility for their study, had access to all the data and controlled the decision to publish.