Abstract
BACKGROUND: The outbreak of SARS-CoV-2 in 2019 was accompanied by a rise in the popularity of conspiracy theories. These theories often undermined vaccination efforts. There is evidence that the spread of misinformation about COVID-19 is associated with online social media use. Online social media enables network effects that influence the dissemination of information. It is important to distinguish between the effects of using social media and the network effects that occur within the platform. OBJECTIVE: This study aims to investigate the association between the modularity of online social networks and the spread of, as well as attitudes toward, information and misinformation about COVID-19. METHODS: This study used data from the social network structure of the online social media platform Vkontakte (VK) to construct an adjusted modularity index (fragmentation index) for 166 Russian towns. VK is a widely used Russian social media platform. The study combined town-level network indices with data from the poll "Research on COVID-19 in Russia's Regions" (RoCIRR), which included responses from 23,000 individuals. The study measured respondents' knowledge of both fake and true statements about COVID-19, as well as their attitudes toward these statements. RESULTS: A positive association was observed between town-level fragmentation and individuals' knowledge of fake statements, and a negative association with knowledge of true statements. There is a strong negative association between fragmentation and the average attitude toward true statements (P<.001), while the association with attitudes toward fake statements is positive but statistically insignificant (P=.55). Additionally, a strong association was found between network fragmentation and ideological differences in attitudes toward true versus fake statements. CONCLUSIONS: While social media use plays an important role in the diffusion of health-related information, the structure of social networks can amplify these effects. Social network modularity plays a key role in the spread of information, with differing impacts on true and fake statements. These differences in information dissemination contribute to variations in attitudes toward true and fake statements about COVID-19. Ultimately, fragmentation was associated with individual-level polarization on medical topics. Future research should further explore the interaction between social media use and underlying network effects.