How Affiliation Disclosure and Control Over User-Generated Comments Affects Consumer Health Knowledge and Behavior: A Randomized Controlled Experiment of Pharmaceutical Direct-to-Consumer Advertising on Social Media

More people are seeking health information online than ever before and pharmaceutical companies are increasingly marketing their drugs through social media.

The aim was to examine two major concerns related to online direct-to-consumer pharmaceutical advertising: (1) how disclosing an affiliation with a pharmaceutical company affects how people respond to drug information produced by both health organizations and online commenters, and (2) how knowledge that health organizations control the display of user-generated comments affects consumer health knowledge and behavior.

We conducted a 2×2×2 between-subjects experiment (N=674). All participants viewed an infographic posted to Facebook by a health organization about a prescription allergy drug. Across conditions, the infographic varied in the degree to which the health organization and commenters appeared to be affiliated with a drug manufacturer, and the display of user-generated comments appeared to be controlled.

Affiliation disclosure statements on a health organization's Facebook post increased perceptions of an organization-drug manufacturer connection, which reduced trust in the organization (point estimate -0.45, 95% CI -0.69 to -0.24) and other users who posted comments about the drug (point estimate -0.44, 95% CI -0.68 to -0.22). Furthermore, increased perceptions of an organization-manufacturer connection reduced the likelihood that people would recommend the drug to important others (point estimate -0.35, 95% CI -0.59 to -0.15), and share the drug post with others on Facebook (point estimate -0.37, 95% CI -0.64 to -0.16). An affiliation cue next to the commenters' names increased perceptions that the commenters were affiliated with the drug manufacturer, which reduced trust in the comments (point estimate -0.81, 95% CI -1.04 to -0.59), the organization that made the post (point estimate -0.68, 95% CI -0.90 to -0.49), the likelihood of participants recommending the drug (point estimate -0.61, 95% CI -0.82 to -0.43), and sharing the post with others on Facebook (point estimate -0.63, 95% CI -0.87 to -0.43). Cues indicating that a health organization removed user-generated comments from a post increased perceptions that the drug manufacturer influenced the display of the comments, which negatively affected trust in the comments (point estimate -0.35, 95% CI -0.53 to -0.20), the organization (point estimate -0.31, 95% CI -0.47 to -0.17), the likelihood of recommending the drug (point estimate -0.26, 95% CI -0.41 to -0.14), and the likelihood of sharing the post with others on Facebook (point estimate -0.28, 95% CI -0.45 to -0.15). (All estimates are unstandardized indirect effects and 95% bias-corrected bootstrap confidence intervals.)

Concern over pharmaceutical companies hiding their affiliations and strategically controlling user-generated comments is well founded; these practices can greatly affect not only how viewers evaluate drug information online, but also how likely they are to propagate the information throughout their online and offline social networks.