Drug advertisements aimed at consumers may not be having the effect on sales that opponents and proponents of the practice assume they do, a new study suggests.
The analysis, by researchers from Harvard Medical School and the University of Alberta, looked at Canadian sales data for three drugs that were heavily advertised in the United States, ads which Canadians watching U.S. television would have seen.
The researchers found no evidence of a spike in sales for two of the drugs after the TV ads started to run. There was a marked increase in sales for a third drug but the effect was short-lived.
“I think that we’ve shown that the effects are pretty unimpressive for the three drugs we’ve looked at,” said Harvard professor Stephen Soumerai, the senior author. “Two out of three there isn’t an ounce of effect.”
The study was published today in the British Medical Journal’s online edition. The authors say it is the first to actually test for evidence of an impact of drug ads by using a control group.
For this study, the researchers took advantage of Canada’s linguistic divide, comparing sales for the three drugs in most of anglophone Canada to sales in Quebec. The authors assumed Quebecers watch much less U.S. television than other Canadians and therefore would see fewer drug ads.
Direct-to-consumer drug advertising is illegal in most countries around the world, including Canada. In Canada, media giant Canwest is fighting a court challenge of the ban, saying it violates the right to free expression enshrined in the Charter of Rights and Freedoms.
Currently, Health Canada allows drug makers to advertise the name of a drug without stipulating what it is for, or advertise about a medical condition, while urging sufferers to seek medical help. Health Canada does not require cable or satellite TV operators to block drug ads on U.S. channels available to Canadians.
Only two countries, New Zealand and the United States, allow direct-to-consumer drug advertising.
In the latter, it’s a multibillion-dollar enterprise; it is estimated the U.S. pharmaceutical industry spends about $5 billion a year advertising prescription medications to the public through TV, radio and print ads.
Studies have suggested they do it for a reason, said Barbara Mintzes, a University of British Columbia drug policy analyst who specializes in direct-to-consumer advertising.
Mintzes said one U.S. study estimated drug companies rake in $4 for every $1 they spend on advertising. Another, by IMS Health, found on average pharmaceutical manufacturers saw a return of $2.20 for every $1 spent on consumer advertising, with that figure rising to $3.66 for every $1 spent on advertising of so-called blockbuster drugs.
Mintzes, who is with UBC’s Therapeutics Initiative, has done a number of studies on the impact of drug ads. One in particular found people who ask their doctors for a prescription for a drug they’ve seen advertised are substantially more likely to leave with a prescription for that drug than people who do not ask for new medication.
Rather than seeing this new study as showing little impact of drug ads, she focused on the fact sales did increase for one of the drugs, tegaserod, which was sold by the brand name Zelnorm.
The drug, sold for irritable bowel syndrome and constipation, was the subject of award-winning ads in which the words “I feel better” were projected onto the abdomens of actresses.
A few years after being brought to market, the drug was withdrawn in both the United States and Canada amid concerns users were at greater risk of suffering a heart attack or stroke.
The two other drugs studied were etanercept (Enbrel), a rheumatoid arthritis drug administered intravenously and mometasone (Nasonex), a nasal steroid spray for allergy symptoms. There were no differences in prescribing rates for the drugs in Quebec and the rest of Canada, suggesting drug ads didn’t drive up sales.
