The effect of competing direct-to-consumer advertising campaigns on the use of drugs for benign prostatic hyperplasia: time series analysis

J Gen Intern Med. 2015 Apr;30(4):514-20. doi: 10.1007/s11606-014-3063-y. Epub 2014 Oct 23.


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.

Publication types

  • Observational Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Direct-to-Consumer Advertising / methods*
  • Direct-to-Consumer Advertising / trends
  • Dutasteride / therapeutic use
  • Humans
  • Inappropriate Prescribing / prevention & control
  • Inappropriate Prescribing / trends
  • Interrupted Time Series Analysis / methods*
  • Interrupted Time Series Analysis / trends
  • Male
  • Prostatic Hyperplasia / drug therapy*
  • Prostatic Hyperplasia / epidemiology
  • Sulfonamides / therapeutic use
  • Tamsulosin
  • United States
  • Urological Agents / therapeutic use


  • Sulfonamides
  • Urological Agents
  • Tamsulosin
  • Dutasteride