Does Direct-to-Consumer Advertising Affect Physicians’ Prescribing Practices?

Direct-to-consumer advertising (DTCA) of prescription medication remains forbidden in most of the world. But, in the US, such ads have become ubiquitous in mainstream media since the US Food and Drug Administration relaxed its broadcast guidance in 1997. Psychiatric medications are some of the most heavily advertised—and highest selling (ie, “blockbuster”)—drugs.

My colleague, Miriam M. Midoun, ScM, and I conducted a systematic review to examine how all of that advertising has affected patient and physician behavior. We became interested in this topic when we realized that only one previous systematic review had examined the benefits and harms of DTCA. The review found that DTCA was associated with increased physician prescribing, but it was published over 10 years ago and included only 1 study of psychiatric medication. We aimed to update the DTCA literature by evaluating psychiatry-relevant studies, defined as studies focusing specifically on psychiatric medication or encompassing a range of medications including psychiatric. Two questions guided our review: (1) How does DTCA affect patient requests for advertised medication? and (2) How does DTCA affect physician prescribing in response to patient requests?

We conducted a comprehensive search of online databases and reference lists (1999–2014) to identify studies evaluating the effects of DTCA on patient and/or physician behavior. Studies had to be conducted in “real time”: we excluded investigations using retrospective reporting (ie, patient or physician recall of past behavior) in order to minimize bias associated with inaccurate recall. For each study, we looked at both the results and quality of methods used.

Much to our surprise, our review identified only 4 studies meeting the criteria. Of these studies, only one randomized clinical trial (RCT) was of strong methodological quality. In this RCT, “standardized patients” (ie, research staff acting as patients) presented to physicians’ offices with different levels of depression severity and made different types of requests for medication they had seen on television. A second study was of moderate methodological quality: this study compared patient and physician behavior across one clinic in the US and one clinic in Canada, where DTCA is prohibited. The remaining studies (Allison-Ottey et al, Parnes et al) were of weak methodological quality and recorded patient and physician behaviors at physicians’ offices.

Based on lack of replication across strong studies, we were not able to make any conclusions with high confidence. With moderate confidence, we concluded that DTCA requests: (1) were granted >50% of the time, (2) prompted higher prescribing volume, and (3) had competing effects on treatment quality. The third conclusion was based on the RCT, which found that DTCA effects were not clear-cut. When patients met full criteria for major depressive disorder, DTCA requests improved treatment quality because patients were more likely to receive needed medication. By contrast, when patients had subthreshold depression (ie, adjustment disorder), DTCA requests reduced treatment quality because patients were more likely to be overprescribed unnecessary medication.

In conclusion, very little research has been conducted on the effects of DTCA. The limited research indicates that DTCA raises prescribing volume for all patients, regardless of severity—making the effects of all of that advertising a bit of a mixed bag.

Financial disclosure:Dr Becker has no relevant personal financial relationships to report.