As its usage has grown, social media has positively and negatively impacted public health. Although social media presents known harms to mental health and spreads misinformation, it also offers rapid dissemination of public health information, expanded access to health resources, and a robust source of health information. However, these benefits are not equitably shared due in part to the "digital divide" of unequal access and use of information and communication technologies. Measurable inequalities in digital access exist among regions, with an eight-fold difference between Central Africa (9.8% social media penetration) and Northern Europe (80.2% social media penetration). Digital inequalities also differ by gender, age, and socioeconomic classes within countries. Increased digital access has been positively associated with improved health information and outcomes related to chronic diseases, infectious disease outbreaks, and reproductive health. Given the expanding role of social media in public health and the emerging evidence on the health benefits of digital access, we argue for reducing digital inequities by (1) creating an enabling government policy and regulatory environment that views digital health access as a social determinant of health; (2) targeting public and private investments to expand digital access for underserved regions and populations; (3) making digital access and use affordable to low-resource populations; and (4) improving digital competency among these groups through digital literacy programs.
Keywords: digital divide; digital equity; health equity; market-driven epidemics; public health; social media.