The pharmaceutical industry spends billions of dollars in the USA each year on direct-to-consumer advertising. According to a new study, such advertising may have no effect at all on sales - at best the impact has been described as modest.
The article by Stephen Soumerai and colleagues from Harvard, was published recently in the British Medical Journal. Only two countries, the USA and New Zealand allow direct-to-consumer marketing of scheduled drugs and most people assume that it must be effective, or the drug companies would not continue. To examine this, Soumerai and his team, used people in French-speaking Canada and a control group. People in Quebec have easy access to television from the USA and so are exposed to these adverts, even though they are not allowed in Canada itself.
The study focused on three drugs, one for rheumatoid arthritis, another for nasal allergy and one for irritable bowel syndrome. All three were available only on prescription and had been on the market for more than 12 months before the direct-to-consumer advertising (DTCA) campaign started. The researchers wanted to find out whether exposure to advertising resulted in a faster increase of prescriptions of these three drugs in the English-speaking parts of Canada, compared to Quebec. By using information from IMS Health Canada, which receives data from approximately 2700 Canadian pharmacies, the authors studied the prescription statistics for these three drugs for a period of five years.
DTCA had no effect at all on the sales of the rheumatoid arthritis drug and that for nasal allergy, the authors reported. The number of prescriptions remains the same in both Quebec and the English-speaking provinces after the DTCA campaigns started.
The third drug, for irritable bowel syndrome, saw a 40% increase in sales. However, this was only an initial rise. After a few years prescription patterns became identical in the USA and Quebec.
The authors think that DTCA of prescription drugs may not be as effective as other forms of advertising because people still have to go through a doctor to obtain a prescription.
