It’s a truism that half of all advertising dollars are wasted, but that no one buying the ads can be sure which half it is. Advertising from the drug companies is ubiquitous: how much of that is doing them no good?
A recent study suggests that the widely reviled direct-to-consumer (DTC) campaigns may be in that category. A paper in the British Medical Journal looks at the cross-border effect of US-based advertising on English-speaking and French-speaking Canadians, on the reasonable assumption that the former group is more likely to pay attention. They picked products that had been on the market for at least a year before the ad campaigns started, and looked at the number of prescriptions among both groups once the ads started running. What they found was no effect on the prescriptions for Schering-Plough’s Nasonex (mometasone) and Wyeth and Amgen’s Enbrel (etanercept), both of which were heavily advertised. Novartis’s Zelnorm (tegaserod, now off the market) did show a 40% rise, which gradually went back down again.
A reasonable theory to explain these results starts by looking at the respective markets. In the case of the first two drugs, a number of different therapies were already available. But Zelnorm was pretty much the only thing available in Canada for irritable bowel syndrome. It could be that DTC ads are useful in letting patients know that there’s finally something for a disease that previously had few options, but less effective in pushing into a crowded area. There’s also the multiple-step barrier problem – seeing a general practitioner and then a specialist, and so on – which can mitigate the effect of advertising, depending on the drug.
But the people who would know these effects best aren’t talking: the marketing departments of the drug companies themselves. As I’ve pointed out here before, the whole purpose of advertising is to make money: if you don’t increase sales enough to more than cover the cost of the ads, you’re clearly wasting your time. And that’s why I don’t have a lot of patience with outraged comparisons of pharma R&D budgets to marketing budgets, because the latter are there to bring in even more money for the former.
If, though, some of these marketing campaigns really are wasted money, then clearly that spending needs to be redirected. And that’s what makes me wonder. No one keeps a closer eye on prescription trends than the companies that sell the drugs, and they’re in the best position to see if a given ad campaign is doing anything or not. Even allowing for the usual human quota of inertia and incompetence, it would seem that DTC campaigns must be doing something for the companies involved, at least in many cases, or they wouldn’t exist at all. It’s also worth keeping in mind that what they may be doing is not so much boosting the number of prescriptions written as keeping them from falling. In the case of the drugs in the BMJ study, you have to wonder if the normal trend would have been for the number of scripts to have declined, while the ad campaigns held them steady.
That can be hard to prove, of course, and no doubt there are some marketing strategies that have far outlived their usefulness on just that kind of reasoning. But overall, I have trouble believing that DTC campaigns are useless across the board. Some of the marketing folks are weasels, but they’re not dumb ones. (It's also important to remember that DTC ads are only 5 to 10% of the total amount spent on drug promotion, according to the figures I've seen). In the end, I can agree with this statement from the paper:
Until we better understand how direct to consumer advertising modifies prescribing for particular drugs, debates about its positive and negative consequences will continue to be based on conjecture rather than strong evidence.