A meta-analytic review of health information credibility: Belief in physicians or belief in peers?

Background: Despite the large corpus of literature on the credibility of health information, results of studies that examined the effect sizes for relationships between credibility and expertise/trustworthiness are inconsistent and have drawn attention to the ambiguity and uncertainty that surrounds the relationship between these constructs in the literature. Objective: This study aimed to provide an estimate of the magnitude of the relationship between manipulated expertise and trustworthiness in predicting health information credibility and to search for potential moderators of the relationship. Method: Comprehensive searches of the Communication & Mass Media Complete, PubMed, PsycINFO, Web of Knowledge, and Medline databases were used to identify potentially eligible studies. No year range was set in this study. Application of strict inclusion and exclusion criteria identified 20 studies, which were analyzed using the R package. Results: Results indicated that manipulated expertise correlated with health information credibility at a higher level than did trustworthiness in the online but not offline context, and that sample characteristics (student vs. nonstudent populations; age of participants) as well as the year of publication of the study were significant moderators of the relationship. Conclusion: This meta-analytic review of the literature has contributed to knowledge about how health information is received and processed by those who seek it. While participants in studies included in this research perceived health information to be more credible when provided by an expert rather than a layperson, their perceptions were moderated by demographic characteristics. This highlights the importance of moderator analyses and provides guidance for future research and practice in health information management.