Even though drugmakers spent an estimated $3 billion in 2005 on those DTC ads in the US, the effort apparently failed to result in more prescriptions, according to researchers at Harvard University and the University of Alberta.
"People tend to think that if direct-to-consumer advertising wasn't effective, pharma wouldn't be doing it," Harvard Medical School's Stephen Soumerai says in a statement. "But as it turns out, decisions to market directly to consumers are based on scant data."
The researchers used French-speaking Quebec residents as their control group. Although DTC ads are illegal in Canada, English-dominant Canadians see a great deal of US advertising, but French-speaking Quebecois see far less and get most of their news from French-language media. As a result, they are less likely to be influenced, the researchers reported in the British Medical Journal.
Using information from IMS Health Canada, the researchers analyzed prescription statistics for each of these three drugs for a five-year period. They found that for two of the drugs, Amgen's Enbrel and Schering-Plough's Nasonex, DTC ads had no effect. Prescription patterns in English-speaking Canada and in Quebec remained identical both before and after DTC campaigns began.
Sales for Novartis' Zelnorm, however, did spike in English-speaking Canada as soon as ads appeared. While scrips increased by over 40 percent, this jump was relatively short-lived, and after a few years, prescription rates in both groups resumed identical patterns, they reported. A similar analysis of US Medicaid scrips found a slightly higher, but similarly brief, jump in sales.
"A person needs to see an ad, get motivated by that ad, contact their doctor for an appointment, show up at the appointment, communicate both the condition and the drug to the doctor, convince the doctor that this drug is preferable to other alternatives, then actually go out and fill the prescription," Soumerai tells Reuters. "This is a chain of events that can break at any point."
In April, a Kaiser Family Foundation report found 91 percent of adults surveyed had seen or heard DTC ads, but just one-third spoke to a doctor about a drug they saw advertised, and 54 percent got a scrip for a different drug. Among doctors, 76 percent said they sometimes recommend a different drug to a patient who mentions an ad and 5 percent said they frequently gave patients the drug.