Background: Direct-to-consumer advertising (DTCA) remains a controversial issue, with concerns that it leads to unnecessary and inappropriate prescribing. Whether DTCA shifts prescribing from first-line (guideline-recommended) therapy to second-line drugs has not been studied. Objective: The purpose of this study was to determine the impact of sequential DTCA campaigns for two drugs used to treat benign prostatic hyperplasia (BPH): one newer agent, dutasteride (Avodart®), and one older first-line agent, tamsulosin (Flomax®). Design: Interrupted time series analysis was used to assess the impact of each DTCA campaign using data on consumer “response” from Google Trends and dispensed prescriptions from IMS Health. Participants: We analyzed data for the United States from January 2003 to December 2007. Intervention: DTCA for dutasteride and tamsulosin commenced on July, 2005 and April, 2006, respectively. Main Measures: Monthly Internet search volume (scaled from 0 to 100) for the advertised trade name of each drug and monthly U.S. prescription rates per 1,000 population were analyzed. Key Results: The dutasteride campaign was associated with an increase in Internet searches for both “Avodart” (level change +31.3 %, 95 % CI: 27.2–35.4) and “Flomax” (level change +8.3 %, 95 % CI: 0.9–15.7), whereas the tamsulosin campaign was associated with increased “Flomax” searches (level change +25.3 %, 95 % CI: 18.7–31.8). The dutasteride campaign was associated with an increase in the prescription of dutasteride (trend = 0.45/month, 95 % CI: 0.33–0.56), but a larger impact was observed with tamsulosin prescriptions (trend = 0.76/month, 95 % CI: 0.02–1.50). Similarly, the tamsulosin campaign was associated with an immediate fourfold increase in the prescribing of tamsulosin (level change +5.76 units, 95 % CI: 1.79–9.72) compared to dutasteride (level change +1.47 units, 95 % CI: 0.79–2.14). Conclusions: DTCA was associated with the utilization of drugs to treat symptomatic BPH. However, both campaigns were associated with greater increases in the use of the guideline-recommended first-line agent. DTCA campaigns may increase the overall levels of guideline-recommended treatments to a greater extent than the specific advertised agents.
Bibliographical noteFunding Information:
Sean Skeldon is supported in part by the CIHR and the Western Regional Training Centre (WRTC) for Health Services Research. Katy Kozhimannil is supported by a grant from the Building Interdisciplinary Research Careers in Women’s Health BIRCWH) program (grant number K12HD055887), with funds from the Eunice Kennedy Shriver National Institute of Child Health and Human Development, the Office of Research on Women’s Health, and the National Institute on Aging, at the National Institutes of Health, administered by the University of Minnesota Deborah E. Powell Center for Women’s Health. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. Sumit Majumdar holds the Endowed Chair in Patient Health Management (Faculties of Medicine & Dentistry and Pharmacy & Pharmaceutical Sciences, University of Alberta) and receives salary support as a Health Scholar of the Alberta Heritage Foundation for Medical Research and Alberta Innovates - Health Solutions. Michael Law reports grants from the Canadian Institutes of Health Research during the conduct of the study, and personal fees from Health Canada outside the submitted work.
© 2014, Society of General Internal Medicine.
- Advertising as topic
- Benign prostatic hyperplasia
- Health policy