Effect of direct-to-consumer drug ads unexpected

September 12, 2006

University Park, Pa. -- Television ads for prescription drugs are everywhere, enticing people to ask their doctors for this drug or that one, but the effect this type of ad has on American health care may be more complicated than simply inducing patients to choose one brand or the other, according to a team of researchers.

"Up until 1997, manufacturers could not say both the product's name and what it was used for, in a TV ad," said Andrew N. Kleit, professor of energy and environmental economics and member of Penn State's Center for Health Care and Policy Research.

Since 1997, direct-to-consumer ads have flourished, even with the requirement that the ads must list all the potential side effects and counter-indications. Some critics suggest that the ads get people to take the medications when they do not need them or are not good for them. Others argue that the ads are important to tell people that a medical solution to the problem is now available. Still others suggest that the ads make people more health conscious and spur them on to get the treatment that they need, no matter which medication they eventually use. However, little research covers the effects of these television advertisements.

Kleit and a team of researchers from Medical University of South Carolina including project principal investigator David Bradford, professor, health administration and policy; Paul J. Nietert, assistant professor, biostatistics, bioinformatics and epidemiology; Terrence Steyer, assistant professor, family medicine; Thomas McIlwain, assistant professor health administration and policy; and Steven Ornstein, department of family medicine, investigated how drug ads for two osteoarthritis drugs influenced patients' medical visits and doctors prescribing the drug.

The team report their work on the two drugs, Merck's Vioxx and Pfizer's Celebrex, in the September/October issue of Health Affairs. Merck voluntarily removed Vioxx from the market in 2004 due to increased risk of heart attack and stroke. "We studied how prescriptions to patients with osteoarthritis for these two drugs responded to changes in television advertising over the 2000 to 2002 time period," the researchers reported.

The researchers found that the direct-to-consumer advertising of Vioxx and Celebrex had positive effects on patient flow, increasing the numbers of patients seeking treatment for osteoarthritis.

The researchers report that "the effect of Vioxx direct-to-consumer advertising was consistently positive, increasing the proportion of osteoarthritis patient visits for which a prescription was written for Vioxx."

The Celebrex advertising was, however, associated with higher rates of Vioxx prescribing, but was not associated with significant changes in prescribing for Celebrex. Possibly, strong efforts by Pfizer drug representatives marketing Celebrex to physicians had already grown the Celebrex prescription base. Another possibility is that the heavy advertising by Merck for Vioxx embedded that brand in people's minds early on and Celebrex ads simply reinforced the class of drugs rather than a specific brand.

Using an extensive database at the Medical University of South Carolina, the researchers had access to information from 500 health-care providers across the United States. The study focused on those patients who came in for treatment of osteoarthritis and used 57 doctors' offices from 44 different U.S. markets.

Researchers used the number of ads broadcast each month as the measure of direct-to-consumer advertising, and they paired patients and physicians with the closest media markets.

The researchers looked at the number of visits in a practice each month by osteoarthritis patients, the number of patients who were prescribed Celebrex, and the number of patients who were prescribed Vioxx. Researchers counted all prescriptions whether new or a renewal. They compared the patient numbers and Celebrex or Vioxx prescriptions with the numbers of ads.

The researchers did find that direct-to-consumer ads for Vioxx and Celebrex influenced doctors' prescribing and patient behaviors.

"These ads convinced more people to visit their doctors for treatment of osteoarthritis," said Kleit of Penn State. "Interestingly, the Celebrex ads were not very good at getting people to ask for or prescribe Celebrex, but did influence visits to the doctor and Vioxx prescriptions, exhibiting a class effect."

The Agency for Health-care Research and Quality and the National Heart Lung and Blood Institute of the National Institutes of Health supported this research.

(Media Contacts)

Last Updated March 30, 2010