Objectives: Messages from organizations with high, compared to low, credibility may be more persuasive. Whereas the tobacco industry has long recognized the importance of credibility in promoting its messages and public image, the source credibility of key tobacco control organizations has gone largely unmeasured. To assess credibility of a key tobacco regulator, we developed a scale of the US Food and Drug Administration (FDA) tobacco-related credibility.
Methods: We developed and tested 30 items reflective of the dimensions of source credibility (trust, expertise, and public interest) and FDA's tobacco regulatory roles in a sample of 1353 US adults and assessed reliability and validity.
Results: Factor analysis identified 3 dimensions of the FDA Tobacco Credibility Scale (FDA-TCS): public interest, trust, and expertise. The 3 subscales showed evidence of reliability and convergent validity; all subscales were correlated with general FDA credibility and trust in government. Those who knew that the FDA regulates tobacco scored higher on the trust and expertise subscales. The subscales were also associated with support for potential regulations, suggesting criterion-related validity.
Conclusions: The FDA-TCS allows for an understanding of the impact of credibility on responses to the FDA's tobacco control communications and regulatory efforts.
Keywords: health communication; public opinion; scale development; source credibility.