Restrictions on Pharmaceutical Detailing Linked To Increase in Generic Drug Prescription Interview with:

Ian Larkin, PhD</strong> Assistant Professor of Strategy UCLA Anderson School of Management

Dr. Ian Larkin

Ian Larkin, PhD
Assistant Professor of Strategy
UCLA Anderson School of Management What is the background for this study?

Response: The study examined whether restrictions put in by medical centers on salesperson visits to physicians, known as “detailing,” affected subsequent physician prescribing behavior. Detailing represents the most prominent form of pharmaceutical marketing. Detailing visits allow the sharing of scientific information, but they also often involve small gifts for physicians and their staff, such as meals.

Pharmaceutical companies incur far greater expenditures on detailing visits than they do on direct-to-consumer marketing, or even on research and development of new drugs. Specifically, the study examined detailing restrictions put into place by 19 academic medical centers (AMCs) in five states in the U.S. It compared changes in prescribing by thousands of AMC physicians whose practices limited typical elements of detailing visits, such as provisions of meals and educational gifts, to a carefully matched control group of similar physicians practicing in the same geographic regions but not subject to such detailing restrictions.

The study, which included more than 25,000 physicians and all 262 drugs in eight major drug classes — from statins to sleep aids to antidepressants, representing more than $60 billion in aggregate sales in the United States — was, to date, by far the most comprehensive to examine the impact of detailing restrictions. The comprehensive and quasi-experimental methodology, which compared prescribing behavior before and after implementation of policies, and which included a large matched control group of physicians not subject to policy changes, was an important innovation relative to prior research. The study used prescription data from CVS Caremark, one of the largest pharmacy benefit managers in the United States. What are the main findings?

Response: The study found that the restrictions caused physicians to switch from prescribing drugs that had been detailed (more expensive, patent protected drugs) to prescribing generic drugs in the same class that were significantly cheaper.

Specifically, the study found that detailing policies were associated with a subsequent 1.67 percentage point reduction in the market share of the average detailed drug; before policy implementation, the average detailed drug had a market share of 19.3 percent.

The reduction in total prescriptions due to the policies therefore is about 8% for the average detailed drug. What should readers take away from your report?

Response: The study suggests that detailing may influence physicians in indirect ways.

No medical center completely barred salesperson visits; salespeople could and did continue to visit physicians at all medical centers in the study. The most common restriction put in place was a ban on meals and other small gifts. The fact that regulating gifts while continuing to allow sales calls still led to a switch to cheaper, generic drugs may suggest that gifts such as meals play an important role in influencing physicians. The correlation between meals and prescribing has been well established in the literature, but our study suggests this relationship may be causal in nature. What recommendations do you have for future research as a result of this study?

Response: There are two very fruitful areas of research suggested by the study.

First, researchers could examine the specific restrictions that appear to affect prescribing most – for example, whether banning meals, limiting product samples or limiting appointment times with doctors had the greatest effect on prescribing.

Second, the study is silent on the question of how these changes in prescribing affect patient outcomes. Whether and how information presented in detailing calls benefits patients is obviously a question of first-order importance.

Put together, further research on these two questions would allow a more nuanced discussion of the benefits and costs of the current detailing model. Are there ways to ensure detailing helps doctors make more informed decisions, without introducing conflicts of interest or biased decision making?

Disclosures: Two of the study’s team members are employees of CVS Caremark, which provided the prescription data for the study. The study was partially funded by a grant from the National Institute of Mental Health. Thank you for your contribution to the community.


Larkin I, Ang D, Steinhart J, Chao M, Patterson M, Sah S, Wu T, Schoenbaum M, Hutchins D, Brennan T, Loewenstein G. Association Between Academic Medical Center Pharmaceutical Detailing Policies and Physician Prescribing. JAMA. 2017;317(17):1785-1795. doi:10.1001/jama.2017.4039

Note: Content is Not intended as medical advice. Please consult your health care provider regarding your specific medical condition and questions.
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