title: Methodological challenges surrounding direct-to-consumer advertising research--the measurement conundrum.
abstract: OBJECTIVE
  Numerous studies have focused on the impact of direct-to-consumer (DTC) prescription drug advertising on consumer behavior and health outcomes. These studies have used various approaches to assess exposure to prescription drug advertising and to measure the subsequent effects of such advertisements. The objectives of this article are to (1) discuss measurement challenges involved in DTC advertising research, (2) summarize measurement approaches commonly identified in the literature, and (3) discuss contamination, time to action, and endogeneity as specific problems in measurement design and application.
  
  
  METHODS
  We conducted a review of the professional literature to identify illustrative approaches to advertising measurement. Specifically, our review of the literature focused on measurement of DTC advertising exposure and effect. We used the hierarchy-of-effects model to guide our discussion of processing and communication effects. Other effects were characterized as target audience action, sales, market share, and profit.
  
  
  RESULTS
  Overall, existing studies have used a variety of approaches to measure advertising exposure and effect, yet the ability of measures to produce a valid and reliable understanding of the effects of DTC advertising can be improved. Our review provides a framework for conceptualizing DTC measurement, and can be used to identify gaps in the literature not sufficiently addressed by existing measures.
  
  
  CONCLUSIONS
  Researchers should continue to explore correlations between exposure and effect of DTC advertising, but are obliged to improve and validate measurement in this area.
authors.affiliation: University of North Carolina at Chapel Hill, Division of Pharmaceutical Policy & Evaluative Sciences, CB 7360-205M Beard Hall, Chapel Hill, NC 27599, USA. rahansen@unc.edu
authors.forename: Richard A
authors.initials: RA
authors.lastname: Hansen
authors.forename: Marcus
authors.initials: M
authors.lastname: Droege
mesh_terms: D000329:Advertising; D003071:Cognition; D015438:Health Behavior; D006801:Humans; D004364:Pharmaceutical Preparations; D012107:Research Design
chemical_list: D004364:Pharmaceutical Preparations