In my group practice, the Yale Medical Group, drug-company sponsored lunches and similar events have been banned. This is part of a trend, at least within academic medicine, to create some distance between physicians and pharmaceutical companies, or at least their marketing divisions. The justifications for this are several, and are all reasonable. One reason is the appearance of being too cozy, which compromises the role of academic physicians as independent experts.

But the primary reason is the belief that “detailing” by pharmaceutical sales representatives has a negative effect on the prescribing habits of physicians. There is reason to believe this may be the case because of cases of bad behavior on the part of pharmaceutical marketing divisions – ghost writing white papers, for example. The concern, backed by evidence, is that pharmaceutical companies introduce spin and bias into the information they provide to physicians, whether though CME, detailing, literature, or sponsored lectures. Even when the information itself is not massaged, it is cherry picked, so in the end physicians are not getting a thorough and unbiased assessment of the facts.

The FDA does heavily regulate the marketing of information about pharmaceuticals, but marketers are very clever about exploiting loopholes and seem to be one step ahead of the regulators.

On the other hand there are those who argue that physicians can handle access to information and they are equipped to take it with a grain of salt and put it into context. Certainly most physicians I speak to believe this about themselves. Further, information provided by pharmaceutical companies may actually improve prescribing habits if it makes physicians aware of new products on the market and new information about the drugs they prescribe. The information itself is FDA approved (or at least should be), even if it is selective and wrapped in spin.

You can defend either position based upon plausibility, which is why I have always been most interested in direct evidence of the effect of pharmaceutical detailing on physician prescribing habits. Mark Crislip has written about this issue before, pointing out that the evidence supports a negative effect of pharmaceutical company contact on physician prescribing. While I generally agree with Mark’s opinion, the evidence seemed a bit preliminary to me. More definitive evidence would be useful in both forming my own opinions and advocating for change.

A new  systematic review of the literature has been published in PLOS Medicine – an excellent opportunity to discuss what the actual state of the evidence is. The authors scoured several databases and came up with 58 studies meeting inclusion criteria. These studies looked at amount of prescribing, prescribing cost, and prescribing quality. They found:

Of the set of studies examining prescribing quality outcomes, five found associations between exposure to pharmaceutical company information and lower quality prescribing, four did not detect an association, and one found associations with lower and higher quality prescribing. 38 included studies found associations between exposure and higher frequency of prescribing and 13 did not detect an association. Five included studies found evidence for association with higher costs, four found no association, and one found an association with lower costs. The narrative synthesis finding of variable results was supported by a meta-analysis of studies of prescribing frequency that found significant heterogeneity. The observational nature of most included studies is the main limitation of this review.

There is definitely a trend in the data, skewed toward a negative effect in each of the three areas. The data seems to be the most clear with regard to frequency of prescribing, which makes sense. Physicians cannot prescribe drugs they are not aware of. There is also the availability effect – we will tend to think of things that are accessible, and that is exactly why pharmaceutical reps want to put their drug names all over promotional material. There is likely also an effect from having free samples available to give to patients. When choosing among equivalent drug options, a prescriber might go with the one that they can give as samples to their patient.

More prescribing is not necessarily bad, if it leads to better care. Underprescribing, in fact, is as much of a problem as overprescribing.

The other two measures were less definitive. Five studies showed increased cost, while five showed no association or decreased cost. Also, five studies showed decreased prescribing quality, while five studies showed no association or ambiguous results. To me these are weak outcomes, without a clear answer. While it is difficult to argue for an improvement in either outcome, these distributions of effects are compatible with there being no net association.

The authors are also careful to point out that most of these studies are observational, not experimental, and so inferring cause and effect is not straightforward. Perhaps there is something inherently different about the quality and prescribing habits of physicians who allow themselves to be detailed more often by pharmaceutical reps.

Further, there may be some situation in which detailing improves prescribing, and others where there is a detrimental effect. We cannot assume a homogeneous effect, and if these differences can be teased out this may inform ways in which regulations and policies can be improved.


After reading this review I am still left with the sense that the data on this important question is currently insufficient – it is mostly observational, and on the two most important questions (cost and quality) the evidence (while trending to the negative) is unclear. What is obvious is that better data would be helpful. Larger and better controlled studies are needed to really look deeply into these important questions, and the research needs to go the next step of trying to identify factors that influence the net effect of pharmaceutical companies being a source of information to prescribers.

Meanwhile I think it is prudent to limit access of drug reps to physicians and their offices, including (especially) in the academic setting. If for no other reason such limitations might motivate pharmaceutical companies to improve their behavior. Perhaps they will figure out that it is in their best interest to provide fair and accurate information about their approved drugs, rather than no information at all.

Since the industry is going through a great deal of change over these types of issues recently, it is also a good opportunity to think of ways to change the system. Like it or not, we have a capitalistic system of drug development. This system has many positives, but frustrating negatives as well. I am in favor of careful and thoughtful regulation (not necessarily more regulation) to keep the industry honest and transparent. Some obvious flaws have been exposed, like ghostwriting articles, and this behavior needs to be banned. But perhaps there are ways to allow pharmaceutical companies to fund the distribution of information about their products, and contribute to physician education about the diseases and disorders for which they sell drugs, while providing a layer of insulation from the bias and spin of those who stand to make money from physician prescribing habits.

Regardless of how we move forward, I would like to see better research data on the question of the impact of pharmaceutical marketing on medical care to help guide whatever future course we take.


Posted by Steven Novella

Founder and currently Executive Editor of Science-Based Medicine Steven Novella, MD is an academic clinical neurologist at the Yale University School of Medicine. He is also the host and producer of the popular weekly science podcast, The Skeptics’ Guide to the Universe, and the author of the NeuroLogicaBlog, a daily blog that covers news and issues in neuroscience, but also general science, scientific skepticism, philosophy of science, critical thinking, and the intersection of science with the media and society. Dr. Novella also has produced two courses with The Great Courses, and published a book on critical thinking - also called The Skeptics Guide to the Universe.