A comprehensive survey of 31,000 adults across 30 countries has revealed a counterintuitive trend: digital health literacy is higher in low- and middle-income nations than in wealthy, high-income countries. Published in Nature Health, the study challenges the long-held assumption that national wealth automatically correlates with stronger digital skills. The research, led by the CUNY Graduate School of Public Health and Health Policy in collaboration with the Barcelona Institute for Global Health, the University of Alabama, and the DNDi, marks the first cross-national examination of how adults evaluate the quality of health information on a global scale. The findings indicate wide variations in how different populations judge health sources and their acceptance of AI-generated content. While medical providers remain the most trusted source globally, cited by 40.7% of respondents, acceptance of AI-generated health information varies significantly by region. Globally, 58.3% of participants expressed willingness to accept such content. However, acceptance rates exceeded 75% in countries like China, India, Pakistan, and Indonesia, whereas they fell below 50% in Canada, the UK, Australia, and several European nations. Younger adults and those with post-secondary education demonstrated greater receptivity to AI than older groups. Assistant Professor Rachael Piltch-Loeb, the study's lead author, emphasized that digital skill is not a function of national wealth. In many developing nations, social media has become a primary gateway for health information, fostering higher digital engagement. Consequently, public health strategies must account for diverse audience needs rather than assuming a one-size-fits-all approach. Communication efforts should prioritize clarity, transparent sourcing, and format diversity to be effective across different cultural and economic contexts. Preferences for information formats and delivery channels also differ sharply by age and location. Combined text-and-image formats are the dominant choice worldwide, though video-only content is preferred by a significant portion of respondents in Egypt, India, and Pakistan. Age demographics heavily influence channel usage; social media serves as the leading platform for adults aged 18 to 29, compared to just 10.6% of those aged 60 and older. Older respondents rely more on traditional, health-care-based channels such as clinic brochures and patient information leaflets. Across all surveyed nations, respondents consistently valued information that is easy to access, easy to understand, and clearly identifies its source. Surprisingly, government approval and endorsement by known medical providers were rated as less critical than these core accessibility features. The authors caution that strategies designed for high-income, institution-led environments may fail in settings where social media and AI-mediated content already define how people encounter health information. The survey was conducted online between August 29 and September 8, 2025, covering adults from 30 countries ranging from Australia to the United States. Researchers used stratified quota sampling within each nation and weighted the data against national benchmarks for age, gender, education, and region to ensure representative results. This work supports the Nature Medicine Commission on Quality Health Information for All research agenda, highlighting the urgent need for tailored communication strategies in the digital age.