Impact of endorser testimonials in direct-to-consumer advertising

Objective: Despite pharmaceutical marketers' increasing use of advertising appeals with celebrity endorser testimonials, impact of such appeals on consumers' reactions to direct-to-consumer (DTC) advertising remains unknown. Therefore, the objectives of this study are to: (1) examine whether DTC ads with testimonials generate positive consumer attitudes and behaviors and (2) examine if attitudes and behaviors influenced by testimonials are the same across productspecific and disease-specific DTC ads, different types of endorsers (e.g., celebrity vs. expert vs. noncelebrity) used in the DTC ads, and consumers with either high or low level of disease state involvement. Methods: Using Qualtrics online survey panel, data will be collected for 840 U.S. adults (aged ≥18 years) in a 3 (endorser type: celebrity/expert/noncelebrity) x 2 (testimonial: present/absent) x 2 (involvement: high/low) x 2 (advertisement type: product-specific/diseasespecific) full factorial design. Participants will be randomly assigned to one of the advertising stimuli, and will be asked to first review the ad and then respond to a questionnaire. Data will be analyzed using a multivariate analysis of covariance to control the impact of confounding variables such as pharmaceutical industry credibility and general attitude toward DTC advertising. Results: Based on previous research in advertising of consumer goods, DTC ads with testimonials (versus without testimonials) are expected to generate more favorable consumer attitudes and behavioral intentions. We expect testimonials by a noncelebrity (versus celebrity or expert) will generate a greater impact on consumer's attitudes and behaviors. Prior research indicates consumers perceive disease-specific DTC ads to be more informative compared with product- specific DTC ads; therefore, diseasespecific (versus product-specific) DTC ads with testimonials will generate more favorable attitudes and behavioral intentions. Consumers with high (versus low) level of disease state involvement who are exposed to testimonial DTC ads are expected to exhibit positive attitudes and behaviors.