Social Science Statistics Blog

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2 September 2008

Study on DTCA creates media attention for causal inference

The British Medical Journal just published an great piece by Michael Law* and co-authors on the (in-)effectiveness of direct-to-consumer advertisement (DTCA) for pharmaceuticals. This issue continues to be political controversial and expensive for companies, and good studies are rare. Mike makes use of the linguistic divide in his home country Canada to evaluate the effectiveness of the ads. Canadian TV stations are not allowed to broadcast pharma ads. The French-speakers have no choice to oblige, but English-speaking Canada gets to watch ads for pharmaceuticals on US TV stations. The results suggest that for the three drugs under study, the effects of DTCA maybe very small and short-term.

An interesting fallout of this work is a wave of media attention for causal inference and identifying counterfactuals. For example the WSJ writes

[...] the new study will draw some attention because it is among the first to compare the behavior of people exposed to drug ads with people who weren't.

And the New Scientist says

However, consumer advertising is usually accompanied by other marketing efforts directly to doctors, making it difficult to tease out the effect of the ads alone.

See here for a longer list of articles at Google News.

I think it's great that the study creates so much interest (meaning it's relevant in real life) and that the media gets interested in research design. I'm curious to see the wider repercussions on both issues.

Law, Michael, Majumdar, Sumit and Soumerai, Stephen (2008) "Effect of illicit direct to consumer advertising on use of etanercept, mometasone, and tegaserod in Canada: controlled longitudinal study" BMJ 2008;337:a1055

* Disclosure: Mike is a recent graduate of the PhD in Health Policy, and a classmate and friend of mine.

Posted by Sebastian Bauhoff at 9:32 PM