Dr Brett says: Well said Dr Parry. It is a major concern to see just how much of a doctors education comes from pharmaceutical reps with no formal medical training. The fact that 'big pharma' can hide studies that are negative and only publish positive ones is also a MAJOR concern. It undermines the whole scientific method of analysis.

DOCTORS are losing faith in medical literature as pharmaceutical companies undermine the integrity of trials, an Adelaide doctor says.

Dr Peter Parry, a psychiatrist and senior lecturer at Flinders University, says trial sponsors use suppression and spinning of negative data to sell their products and that leads to doctors unknowingly making the wrong prescribing choices.

He says poor results are hidden, while positive results are "cherry picked". Articles are often written by marketing-driven ghostwriters.

Another tactic is "disease mongering" to expand the "recognised boundaries of a disease  ... in order to increase prescriptions and sales".

Dr Parry, a member of the Adelaide-based international group Healthy Skepticism, voices his concerns in the latest edition of the journal Bioethical Inquiry.

"The industry and its associated medical communication firms state that publications in the medical literature primarily serve marketing interests," he says.

"Suppression and spinning of negative data and ghostwriting have emerged as tools to help manage medical journal publications to best suit product sales, while disease mongering and market segmentation of physicians are also used to efficiently maximise profits."

Dr Parry says there is now a "crisis of trust", with doctors losing confidence in the information they should be able to rely on.

"It makes me very cautious around prescribing these days," he says.

He says there is an urgent need for stricter policing of trials and more transparency around what they find.

The article emphasises that the tactics are not unique to any company, but are "quite plainly widespread".

A US Senate Finance Committee report released earlier this year was the latest in a string of publications critical of so-called Big Pharma.