The power of advertising means you may get medications you don't need

A study published this month confirms what has often been suspected, that prescription drug advertising not only persuades patients to ask for certain medications but also has a profound influence on what doctors prescribe.

Prescription drug advertising is a $3.2 billion industry in the United States and the study revealed that consumer advertising may have competing effects on health-care quality, by promoting the overuse of drugs in some cases while also averting under use and raising consumer awareness of disease.

The study focused it's attention on antidepressants, as they consistently rank among the top advertised drugs and was a collaborative effort between the University of Rochester Department of Family Medicine and University of California, Davis.

Professor Ronald M. Epstein, M.D. led the research in collaboration with Richard L. Kravitz, M.D., MSPH.

The researchers found that doctors prescribed antidepressants far more often when patients asked for them and it was clear that patients themselves can prompt physicians to provide better care.

Epstein says that although drug ads get patients to prompt their physicians when patients brought up non-commercial information they were more likely to get the correct treatment.

The study conducted from May 2003 to May 2004 used trained actors to pose as patients for the randomized trial, in which visits were made to doctors offices in Rochester, Sacramento and San Francisco. The actors discreetly recorded the visits with small devices hidden in their purses. Doctors were recruited to take part and reimbursed $100 per visit, plus $100 for completing surveys and $75 for staff expenses. When doctors agreed to participate and to being secretly audio-recorded, they were only told that the study would involve seeing patients who would present with a "combination of common symptoms" over the course of a year. After the study was completed, physicians were debriefed and they gave permission to use the data.

The actor-patients were assigned to portray either major depression with moderate severity ( Role 1), or the less-serious adjustment disorder with depressed mood (Role 2). They were divided into groups, and instructed to either ask for a certain drug, Paxil which at the time was widely promoted, or to make a general request for medication, or no request. They also mentioned they had seen a TV advertisement for Paxil, or a special TV segment on depression, and wondered whether a prescription medicine might help them.

The results showed that in major depression (Role 1), doctors prescribed antidepressants 53 percent of the time when Paxil was requested, 76 percent of the time when the actor-patient made a general request for drugs, and 31 percent of the time when no drug request was made.

As expected, prescribing antidepressants was less common in those cases in which the actors portrayed (Role 2): 55 percent when Paxil was requested, 39 percent when a general drug request was made, and 10 percent when no drugs were requested. But the study notes that prescriptions for Paxil accounted for two-thirds of all antidepressant prescriptions given to the Role 2 actors making brand-specific requests and these results are cause for concern as no scientific data supports the use of antidepressants for adjustment disorder, particularly when symptoms are mild and of short duration, and the prescribing of antidepressants in this context is "at the margin of clinical appropriateness."

Doctors were much more likely to consider diagnosing depression, and recording that diagnosis, if the actor-patient made a request for medication. It suggests that if patients can persuade doctors to prescribe drugs they would not otherwise consider, doctors may not be the "stalwart intermediary that the law assumes," warn the researchers.

The National Institute of Mental Health funded the project which is the first to examine the tendency to over-prescribe or under-prescribe a medication.

The researchers do however concede they are unable to definitively determine whether DTC advertising does actually produce the behaviours in real patients that were portrayed by the actors but they do feel the results should be a caution for DTC advertising. On a more positive note the study does highlight the potential for opportunities to improve care in depression and other chronic conditions by using public media channels to expand patient involvement.

The study is published in the Journal of the American Medical Association.