Only in New Zealand and the United States can pharmaceutical companies advertise their products directly to potential consumers. Direct-to-consumer advertising (DTCA) is extensive in the US but a new study from Harvard University has proven that advertising directly to consumers does not increase drug sales to any significant degree and it has no effect at all in some cases.

Like most of us who wouldn’t do something if we know it doesn’t work, Stephen Soumerai, a professor at Harvard Medical School, says that’s not what’s happening with the pharmaceutical industry. His is the first study ever conducted that compares DTCA to the number of prescriptions written for a publicly advertised drug.

The US Food and Drug Administration (FDA) allowed the pharmaceutical industry to market directly to consumers in 1997. The advertising expenditures of the industry shot up 330% over the following ten years, topping $5 billion in 2005.

To find a population that could be compared with and without DTCA of pharmaceuticals, the Harvard research team turned to Canada, where both English and French are spoken. Drug-related DTCA isn’t allowed in Canada but English-language television and radio signals from the US can be picked up in Canada and American magazines, newspapers, and other publications cross the border, along with the drug ads they contain.

English is the accepted language across much of Canada but the province of Quebec is home to 7.5 million people, 80% of whom speak French as their language of choice. In Quebec, television, radio, and print media are more likely to be in French, meaning only a very small segment of the population would be influenced by US-made advertising.

The Harvard team focused on just three prescription medications - Enbrel, for rheumatoid arthritis; Nasonex, for nasal allergies; and Zelnorm, for a specific form of irritable bowel syndrome. The team turned to IMS Health Canada, where prescription statistics from 2,700 Canadian pharmacies would identify how many, and where, prescriptions had been written over a five-year period for each of the three drugs in question.

The team compared the number of prescriptions written for each of these drugs in English-speaking parts of Canada with the number of prescriptions written in Quebec, looking for an increase in the number of prescriptions written in English-speaking areas that corresponds with each drug’s advertising campaigns.

There was no change at all to the prescription pattern for Enbrel and Nasonex. In both Quebec and English-speaking Canada and before and after the DTCA campaigns kicked off, the number of prescriptions for these two drugs remained statistically identical.

The DTCA campaign for Zelnorm did produce a brief but noticeable spike in English-speaking Canada, with 40% more prescriptions written after advertising than before. The rate of prescriptions returned to the rate of prescriptions written in Quebec in just a few years, however. Prescription records for the US Medicaid program produced the same brief spike in prescriptions.

The research team suggests the very lengthy process by which a patient goes from seeing an ad to actually purchasing a prescription of the advertised drug as a reason why DTCA is so ineffective. With so many other products, a consumer sees an ad and then buys the product. With prescriptions, the consumer must schedule a doctor’s appointment, keep it, explain to the doctor why the advertised drug is desired and what symptoms it is expected to relieve, and then, if a prescription is actually written, travel to a pharmacy to finally have the prescription filled.

There are alternatives, both prescription and over the counter, for Enbrel and Nasonex that doctors are more likely to prescribe before writing a prescription for either of these drugs. Zelnorm, however, is the only drug available that treats a form of irritable bowel syndrome characterized by constipation, a situation that would have made it a popular new treatment alternative with or without the advertising. Unfortunately, Zelnorm lost FDA approval in March 2007 after concerns arose that the drug increased the risk for stroke and heart attack.

The Harvard team concludes that there is nothing more effective than a pharmaceutical representative promoting his or her products directly to the physicians who write the prescriptions.

The study, published online September 2 in the British Medical Journal, was funded by Harvard Medical School, Harvard Pilgrim Health Care, The Alberta Heritage Foundation for Medical Research, the Agency for Healthcare Research and Quality, and the Social Sciences and Humanities Research Council of Canada.

Source: Harvard Medical School