“Are physicians easy marks?” ask Natalie Mizik of Columbia University and Robert Jacobson of the University of Washington in a paper of the same name. “To the contrary, our results show that physicians are “tough sells” in that sales force activity has modest to veryinfluence on prescribing behavior.”
A related study by a second set of researchers suggests that distributing drug samples is less a method to sway physicians than a way of contrasting medications and helping manufacturers maintain market share.
The papers are being presented today at the INFORMS Marketing Science Conference, which takes place at the Robert H. Smith School of Business in the University of Maryland. The conference began on June 13 and concludes on June 15.
Study of Three Drugs
The authors, noting accusations that pharmaceutical sales representatives (PSRs) compromise physician integrity, obtained access to a database that allowed them to assess the impact that interactions with sales reps have on the number of new prescriptions issued by physicians.
The study sample involved three different drugs and 74,075 American physicians. The database contained information for 24 months on the number of new prescriptions issued for a drug by a given physician, the number of ‘detailing’ sales calls the physician received that month for the drug, and the number of free drug samples that the rep left with a physician. The data was provided on condition of anonymity.
The drugs differ: they come from different therapeutic areas; they have been on the market from less than 1 year to 11 years; and they have achieved different levels of commercial success – their annual sales range from under $.5 billion to over $1 billion. In total, the data represent over 4 million interactions between physicians and pharmaceutical sales representatives.
For each of the drugs in the study the authors used statistical modeling and operations research methods to assess the effect that changes in the amount of detailing and sampling had on the number of additional new prescriptions the physician issued over the subsequent six-month period for the drug.
They found that pharmaceutical companies had to invest heavily to produce even aincrease in prescriptions. For the three drugs studied – drug 1 is prescribed by psychologists and psychiatrists, drugs 2 and 3 are prescribed by primary care physicians - the results indicate that it would take an additional .64, 3.11 and 6.54 PSR visits, respectively, to induce one additional new prescription and 6.44, 25.39, and 73.05 additional free drug samples to induce one new prescription.
The authors say that the most important reason why sales reps are having limited influence is that they are not the only source of information for physicians. Doctors consult scientific papers, advice from colleagues, and their own experience when developing prescribing practices.
“Indeed, most physicians view these influences as far more important than that of PSRs,” write the authors. “Many physicians view skeptically or hold negative attitudes toward PSRs. They recognize that information presented is biased toward the promoted drug and is unlikely to be objective.”
Benefit of Drug Samples
In “Prescription Drug Promotion: The Role and Value of Physicians’ Samples Under Competition,” Kissan Joseph of the University of Kansas and Murali K. Mantrala of ZS Associates in Evanston, Illinois use a math model to analyze drug samples’ impact on patients, physicians, and pharmaceutical manufacturers. They conclude that supplying samples plays a positive role in making the choice between medications.
“While critics often argue that this practice adversely affects patient welfare,” they write, “we contend that samples provide a benefit by facilitating the match between drugs and patients’ underlying disease state by reducing the cost of comparing drugs.”
If patients are incorrectly matched to a drug, the paper observes, they lose money and suffer the lack of physical relief from their ailment. Providing free samples helps reduce out-of-pocket cost to patients and alleviates some of the non-financial costs, as well.
Their findings also show considerable variation in sampling across categories. In particular, the demand for samples to treat allergies seems quite high. In contrast, the use of samples among lipid-lowering agents is fairly low.
Surprisingly, they suggest that pharmaceutical companies are often the losers in the samples war, incurring great expense by distributing free samples purely as a defensive marketing tactic to maintain market share.
The Institute for Operations Research and the Management Sciences (INFORMS®) is an international scientific society with 10,000 members, including Nobel Prize laureates, dedicated to applying scientific methods to help improve decision-making, management, and operations. Members of INFORMS work in business, government, and academia. They are represented in fields as diverse as airlines, health care, law enforcement, the military, the stock market, and telecommunications. The INFORMS website is at http://www.informs.org.