Measuring Exposure to Direct-to-Consumer Advertising-A Validation Study in the Context of Cancer-Related Treatment Advertising.

This research examines two recurrent conceptual issues of measuring media exposure in survey research in the context of cancer-related direct-to-consumer advertising (CR-DTCA)-the level of content specificity of survey items and the benefits of providing exemplars to aid recall. We evaluated three candidate measures of cancer patients' self-reported exposure to CR-DTCA; these measures varied in content specificity and provision of ad exemplars. Using data from two distinct population-based surveys, we assessed the performance of each measure based on several reliability and validity criteria. Results across both surveys indicate that all three measures performed equally well in terms of internal consistency, convergent, nomological, and discriminant validity with a few minor differences between these measures. Increased content specificity or inclusion of ad exemplars did not result in better performance of the exposure measures. Participants were able to extrapolate from ad exemplars to report their exposure to broad categories of CR-DTCA. The briefest of the three measures posed the lowest level of survey costs among the three measures and was deployed successfully for both mailed and internet-based survey administration. We discussed future directions for application of these findings in DTCA research for other illness and for media exposure research more generally.