Healthy Skepticism Library item: 17921

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Publication type: news

Hagan P
General practitioners deciding whether to prescribe a new drug are more likely to rely on information supplied by the representative from the pharmaceutical firm that makes it than independent sources of evidence, according to a new British study.
Reuters Health 2003 Jan 16

Full text:

General practitioners deciding whether to prescribe a new drug are more likely to rely on information supplied by the representative from the pharmaceutical firm that makes it than independent sources of evidence, according to a new British study.

“This is disquieting since information from representatives may be misleading, biased, contain inaccuracies that doctors fail to recognise and encourage less rational prescribing,” said researcher Dr. Helen Prosser, from the department of pharmacology and therapeutics at Liverpool Infirmary.

Dr. Prosser and colleagues report their findings in the January issue of the journal Family Practice.

Previous studies on prescribing have looked at how GPs are influenced by evidence for effectiveness of one drug over another. Few have considered the extent to which they are affected by so-called “psychosocial influences” – such as the role of drug representatives, how hospital consultants prescribe and the extent to which patients demand certain drugs.

In their study, Dr. Prosser and colleagues compiled a list of 19 new drugs that came onto the market in the UK between January 1998 and May 1999 and interviewed 107 GPs in the northwest of England about their use.

Each GP was asked to explain the context in which they prescribed the new drugs, how they obtained the information that influenced their decision and the reasons for using the new drug over alternatives.

The results showed most GPs initially became aware of a new drug through sales representatives’ visits. Less influential sources included newspaper reports and what hospital consultants chose to do.

In terms of deciding what to prescribe, drug firms were again the greatest influence, followed by consultants and patients requesting specific treatments.

“Seventy percent of the GPs who saw representatives regarded them as an expedient means of acquiring and processing drug information and keeping up-to-date with new products,” the researchers write.

“Although GPs questioned the objectivity of the industry, they generally considered its information to be factually accurate, if selective. GPs felt able to separate credible information from the misleading.’

But the findings show only a small minority of family doctors consult evidence-based sources before deciding what to prescribe. “Peer-reviewed journals were influential for only 17 percent of GPs,” the researchers report. “They cited lack of time, information overload, difficulty in interpretation, irrelevance…and the importance of clinical experience as constraints.”

The researchers conclude that written guidance to GPs—such as that produced by the National Institute for Clinical Excellence (NICE) in England and Wales—may not be enough to influence their habits.

Instead, they conclude, it may necessary to deploy “multifaceted approaches” to changing practice. “A key issue is the provision of reliable, easy to digest independent assessments of new drugs, communicated by a trusted source.”