Doctors are advised to avoid pharmaceutical promotion: that was our conclusion following the first review to exhaustively examine all the available literature on the information from drug companies to doctors.

Leading an international team with expertise in this area, I found no benefit for doctors and their prescribing after seeing pharmaceutical representatives, attending sponsored drug meetings and reading journal advertisements among other types of promotion. The findings, published today in the online journal PLoS Medicine, are based on our search of the literature involving over 7000 articles, with 58 finally being included in the review.

Contrary to pharmaceutical company claims that their promotional activities are educational and beneficial, we found that in almost all cases drug company information was associated with reduced prescribing quality and increased prescribing costs or no change.

One study found that doctors using more pharmaceutical company information had less rational prescribing, while another found that increasing numbers of pharmaceutical company representative visits resulted in less prescribing guideline adherence by doctors.

Another study found that physicians with low prescribing costs were less likely to see pharmaceutical representatives regularly and were more likely to have rarely or never read promotional mail or journal advertisements from pharmaceutical companies than physicians with high prescribing costs.

No studies looking at pharmaceutical company information found that promotion reduced prescribing frequency and many found an association with increased numbers of prescriptions, contrary to claims by doctors that they are not influenced by pharmaceutical company information.

One study found that pharmaceutical sales representative visits were associated with greater increases in market share for new drugs than was positive scientific information about these drugs. The same study also found that journal advertisements were associated with increased market share than positive scientific information in these journals.

The major limitation of this study is that most of the studies are observational and it is not possible to draw definitive conclusions about the effects of drug company information on doctors. It may be that doctors who do a lot of prescribing attract more promotion from pharmaceutical companies. This study does not exclude the possibility that there may also be situations where prescribing is improved.

Pharmaceutical companies appear to be satisfied that their promotional activities are influencing doctors, increasing market share and prescribing. In 2004, pharmaceutical companies spent $57 billion dollars on promotion in the United States — it’s unlikely they would do this if it was not in the interest of their shareholders. The policy implications of these findings are clear.

We call on governments, serious about evidence-based policy, to legislate to form an independent pool of educational funds for doctors. Financial incentives should be provided to encourage pharmaceutical company contribution to this fund which would encourage the rational use of their products.

We also call on policy makers to set up an independent body to regulate promotion and ask government to invest heavily in independent sources of information for doctors. This will allow pharmaceutical companies to do what they do best: concentrate on converting basic scientific discoveries into therapeutic products.

After conducting this review, it is clear to me that doctors need to accept that they are influenced by pharmaceutical promotion at least some of the time.

We think that peak doctor bodies need to implement the review’s recommendation to avoid information from pharmaceutical companies unless evidence of benefit emerges. These reforms are likely to be well received by a public keen to get the best evidence-based health care from both doctors and policy-makers.