Abstract Body (Do not enter title and authors here): Background: Mobile health applications (apps) offer promising tools for managing chronic conditions like hypertension and diabetes. However, disparities in access and use—often referred to as the digital divide—may limit their benefits for vulnerable populations. Understanding these disparities is essential for developing equitable digital health strategies.

Objective: To assess the prevalence and predictors of mobile health app use among U.S. adults with hypertension and/or diabetes and to identify sociodemographic, technological, and health-related disparities using nationally representative data.

Methods: Data were drawn from the 2024 Health Information National Trends Survey (HINTS 7), a cross-sectional study of the US adults who are speaking English and Spanish. Adults with self-reported hypertension and/or diabetes (n=3,349) were included. The outcome was self-reported mobile health app use. Independent variables included sociodemographic characteristics, technological access (smartphone ownership, internet use), digital literacy (confidence using devices, frustration with technology, search skills), and health-related factors (chronic conditions, smoking, alcohol use, physical activity, and sleep). Survey-weighted multivariable log-binomial regression was used to estimate adjusted prevalence ratios (RRs) and 95% confidence intervals (CIs).

Results: Significant disparities in app use were observed. Adults aged 65–74 (RR=0.70, 95% CI: 0.56–0.88) and 75+ years (RR=0.50, 95% CI: 0.35–0.71) were less likely to use apps than younger adults. Males (RR=0.85, 95% CI: 0.74–0.97) were less likely to use apps than females. Higher income (≥$100,000: RR=1.39, 95% CI: 1.06–1.81) and education (college+: RR=1.42, 95% CI: 1.17–1.73) were associated with greater use. Lack of smartphone (RR=0.42, 95% CI: 0.24–0.75) and never using the internet (RR=0.07, 95% CI: 0.01–0.46) were strong barriers. Lower digital confidence (RR=0.74, 95% CI: 0.56–0.97) and high frustration with technology (RR=0.61, 95% CI: 0.43–0.87) were also associated with reduced use. Health-related factors were not significantly associated with app use.

Conclusion: Substantial disparities in mobile health app use persist among U.S. adults with hypertension and/or diabetes, particularly by age, sex, income, education, and digital access. Addressing technological barriers and digital literacy is critical to promoting equitable engagement with digital health tools.