Direct-to-consumer advertising
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* John R. Graham

*   © 2004 Canadian Medical Association or its licensors

Barbara Mintzes and colleagues1 seem to demonstrate that direct-to-consumer advertising (DTCA) has net benefits, despite their own pessimistic interpretation. Patients who requested advertised drugs received them in 86.5% of cases, whereas only 26.2% of patients who did not make a request received a prescription. However, 74.3% of patients who requested nonadvertised drugs received prescriptions. Thus, although DTCA was associated with a greater proportion of requests that were fulfilled, the effect was minor relative to other, unexplained, reasons for requesting prescriptions.

For prescriptions that were given without being requested, physicians considered only 12.1% “possibly” or “unlikely” to be appropriate for similar patients. However, for requested prescriptions for advertised drugs, the share was 50.0%, and for requested prescriptions for nonadvertised drugs it was 39.6%. Thus, the same principle applies here as above.

Of prescriptions for advertised drugs, half were unambiguous (i.e., were not associated with physician ambivalence about appropriateness), and it is not stated how many, if any, of these ambiguous prescriptions had negative outcomes. I have shown elsewhere2 that if less than 42% of ambiguous prescriptions cause negative outcomes, DTCA has a net positive effect, and the true value is probably less than this. A US Food and Drug Administration (FDA) survey of 500 American physicians reported that in 82% of cases, the fact that a patient had seen a DTC ad did not create any problems in the physician's interaction with the patient.3

In an open society, those who advocate restricting freedom of speech must make an ironclad case for public harm when they argue that drug-makers should not enjoy the same rights as the rest of us. Mintzes and colleagues are far from doing so.

**John R. Graham** The Fraser Institute Vancouver, BC

## Footnotes

*   *Competing interests:* The author's employer has received donations from research-based drug-makers, and the author has received speaking fees from research-based drug-makers.

## References

1.  1. Mintzes B, Barer ML, Kravitz RL, Bassett K, Lexchin J, Kazanjian A, et al. How does direct-to-consumer advertising (DTCA) affect prescribing? A survey in primary care environments with and without legal DTCA. CMAJ 2003;169 (5): 405-12.
    
    [Abstract/FREE Full Text](http://www.cmaj.ca/lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiQUJTVCI7czoxMToiam91cm5hbENvZGUiO3M6NDoiY21haiI7czo1OiJyZXNpZCI7czo5OiIxNjkvNS80MDUiO3M6NDoiYXRvbSI7czoyMjoiL2NtYWovMTcwLzUvNzY4LjIuYXRvbSI7fXM6ODoiZnJhZ21lbnQiO3M6MDoiIjt9) 

2.  2. Graham JR. CANSTATS Bulletin: *Who's afraid of prescription drug advertising?* Toronto: Canadian Statistical Assessment Service; 2003 Sep 8. Available: [www.canstats.org/readdetail.asp?id=574](http://www.canstats.org/readdetail.asp?id=574) (accessed 2003 Oct 3).
    
    

3.  3. Aikin KJ. *Direct-to-consumer advertising of prescription drugs: physician survey preliminary results* [MS PowerPoint presentation]. Rockville (MD): US Food and Drug Administration, Center for Drug Evaluation and Research: 2003 Jan 13. Available: [www.fda.gov/cder/ddmac/globalsummit2003/index.htm](http://www.fda.gov/cder/ddmac/globalsummit2003/index.htm) (accessed 2003 Nov 6).