TV advertising of prescription drugs may increase visits to doctor not actual sales

TV advertising of prescription drugs may be prompting more people to visit their doctors rather than substantially increasing sales of advertised drugs, according to research led by the Medical University of South Carolina (MUSC).

Initial results of an ongoing project at MUSC that looks at Direct to Consumer Advertising (DTC) for Cox-2 inhibitor drugs will be published in the September/October issue of the journal Health Affairs. Researchers from Pennsylvania State University also are participating in the study.

Because the use of DTC by pharmaceutical companies continues to accelerate, researchers wondered what the advertising was actually influencing. The team reported on two drugs, Merck's Vioxx and Pfizer's Celebrex, in a study that sought to determine whether pharmaceutical companies can influence physician and patient decisions about adopting pharmaceutical therapy.

"It's not been established whether DTC has a larger effect on stimulating prescribing by physicians or on encouraging patients to go visit their physician's more frequently," said David W. Bradford, Ph.D., Director of MUSC's Center for Health Economic and Policy Studies, and lead author of the study. "We found that for both Vioxx and Celebrex, DTC tended to increase visits by patients with osteoarthritis to their physicians," Bradford said. "Once the patients got to the doctor office, advertising was not the biggest factor affecting prescribing. In fact, we tended to find class level effects."

For example, Bradford said that Vioxx advertising led to small increases in the prescribing for both Vioxx and Celebrex. "One conclusion we found is that DTC may not be the universally pernicious practice that people are worried it is," Bradford said. "It does get patients to their doctors and once there, we see mixed results in prescribing." Bradford said this suggests that doctors and patients are making informed decisions.

The Agency for Healthcare Research and Quality and the National Heart Lung and Blood Institute of the National Institutes of Health supported this research, which is also examining the role of DTC in statin prescribing.