Physicians Prescribe Fewer Branded Drugs When Sales Rep Visits are Limited

Marketing pharmaceuticals to physicians by sending sales representatives to clinics is one of the most powerful promotional tools available to drug companies. However, critics of the practice have expressed concerns that these visits could have an inappropriate influence over physician prescribing behaviour.

Researchers at the University of California, Los Angeles (UCLA), and Carnegie Mellon University (CMU), have now found that when pharmaceutical sales visits were restricted, doctors changed the way they prescribed drugs to their patients. The results of the study were published in the Journal of the American Medical Association.

The researchers studied the impact of practice-mandated restrictions on pharmaceutical representative visits to doctors’ offices at 19 different academic medical centers. They found that once these restrictions were put in place, physicians were more likely to prescribe cheaper generic drugs over their expensive branded counterparts.

Pharmaceutical sales representatives use a technique known as detailing when they visit doctors’ offices. Detailing involves providing physicians with free meals and small gifts, and is expensive for pharmaceutical companies, however these efforts can be rewarded if they help persuade a doctor to prescribe their medication to patients.

To shed light on the influence of restrictions on detailing and prescription writing, the researchers compared the prescribing behavior of thousands of physicians before, and after, their academic medical centers implemented restrictions on sales rep visits. They also collected data on a control group of physicians practicing in the same geographical area, but without restrictions on detailing.

In all, 25,000 physicians prescribing 262 drugs – including sleep aids, statins and antidepressants – worth over $60 billion in US sales, were included in the study. The study is considered to be the largest, most comprehensive research conducted on the practice to date.

“The study cannot definitively prove a causal link between policies that regulated detailing and changes in physician prescribing, but absent a randomized control, this evidence is as definitive as possible,” said Dr. Ian Larkin, assistant professor of strategy at UCLA’s Anderson School of Management. “We investigated 19 different policy implementations that happened over a six-year period, included a control group of highly similar physicians not subject to detailing restrictions and looked at effects in eight large drug classes. The results were remarkably robust – after the introduction of policies, about five to 10 percent of physician prescribing behavior changed.”

Before the academic medical centers implemented restricted detailing policies, the average drug prescribed by the physicians had a 19.3 percent market share; after implementation of the restrictions, this number dropped by 8.7 percent. According to Larkin and his colleagues, pharmaceutical sales visits could also have indirect influences on prescribing physicians.

“No medical center completely barred salesperson visits; salespeople could and did continue to visit physicians at all medical centers in the study” said Larkin. “The most common restriction put in place was a ban on meals and other small gifts. The fact that regulating gifts while still allowing 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.”

The researchers believe that regulators may need to step in to better manage these conflicts of interest among pharmaceutical companies and prescribing physicians. The study authors warn that relying on individual physicians to regulate this practice may not be sufficient to solve the problem.

“Social science has long demonstrated that professionals, even well-meaning ones, are powerfully influenced by conflicts of interest,” said Dr. George Loewenstein, the Herbert A. Simon University Professor of Economics and Psychology at CMU. “A large body of research also shows that simply disclosing conflicts of interests is insufficient to reduce their influence, and may even exacerbate it. The results from this study underline the effectiveness of, and need for, centralized rules and regulations. We should not put the onus of dealing with conflicts on patients; the best policies are those that eliminate conflicts.”