Kevin MD and Blogborygmi cited this article about the influence of drug sampling on residents’ prescribing behavior. There have been numerous articles of this sort, showing various effects of detailing and sampling by pharmaceutical companies, and considerable controversy has been fueled. Many of the citations have been compiled at No Free Lunch and Healthy Skepticism, organizations which are critical of pharmaceutical industry marketing. Some would like to see marketing disappear as we now know it, and are calling on physicians to refuse to accept literature or even small gifts from drug sales representatives. Others would reduce or curtail the pharmaceutical industry’s support of physician CME.
Most all the critics cite the studies as evidence to back up their recommendation to drastically change the landscape of drug company promotion. But is this evidence strong enough to warrant such a recommendation? Check the above web sites, link to the articles and decide for yourself. At the risk of oversimplification the gist of the studies is that physicians’ prescribing behavior is influenced by pharmaceutical industry promotion. That is, marketing works. Some of the studies suggest that the promotions even influence doctors to prescribe outside established guidelines.
But as I browse this extensive collection of links I discover a weakness. I can not find one study about patient outcomes. Only the surrogate endpoints are examined. So, we can learn a lot from these studies about the effect of marketing on doctors’ attitudes and prescribing behaviors, and it’s all very interesting---indeed fascinating---but what about the clinical bottom line? Unfortunately, research to date provides no answers.
Our adventure in evidence-based medicine has taught us about the hazard of reliance on surrogate endpoints. In the 1970s we knew that surrogate hemodynamic endpoints in heart failure were adversely affected by beta blockade, and were taught that beta blockers were bad for heart failure. Only after years of outcome based studies did we realize we were wrong. We also knew that ventricular arrhythmias were harmful, and that since the surrogate endpoint of frequency of ventricular arrhythmias could be decreased by treatment with Class I-C antiarrhythmic drugs, such treatment must be a good thing. Not until completion of the first adequately powered outcome based study, CAST, did we know how tragic such thinking was.
So while the science concerning the effect of drug company promotion is soft, many observers still think the impact on patient outcomes is negative. Although promotions are certainly biased and the material can be deceptive, the information doctors receive is a mixture of good and bad. Must we assume that the bad influence outweighs the good, or is the reverse equally plausible? We must resist simplistic assumptions. Out in the real world varied and sometimes opposing factors are at play. For example, although Vioxx was heavily promoted and associated with harm there are other examples in which drug companies promote numerous beneficial therapies that are evidence-based and known to be under-utilized such as beta blockers and ACE inhibitors for heart failure and low molecular weight heparins for deep vein thrombosis prophylaxis   .     Who knows how it all balances out?
I don’t rely on drug reps or promotional material to keep current, nor should anyone. There’s no need. Present day information technology makes it unnecessary. We can easily get good quality unbiased information at the point of care. However, a sweeping prohibition against drug reps, samples and industry supported CME is not supported by high level evidence. The jury is still out.