Stanford Study Published in JAMA Network Open Shows CareMessage's Text-Based Health Coaching Matches Human Counselors in Boosting Physical Activity
Randomized trial demonstrates text messaging platform can increase walking by nearly 2 hours per week among participants
SAN FRANCISCO, Sept. 9, 2025 /PRNewswire/ -- CareMessage, a leading digital health platform focused on serving low-income populations, today announced the publication of research in JAMA (Journal of the American Medical Association) Network Open demonstrating a customized text messaging system is as effective as human telephone counseling for increasing physical activity among Latino adults.
The randomized clinical trial, led by Stanford University investigators in partnership with CareMessage with funding from the National Institute of Diabetes and Digestive and Kidney Diseases, followed 280 predominantly Latino adults ages 35-79 across five Northern California counties from 2015-2018. Participants were inactive adults with a mean BMI of 33.1, with more than half (51.6%) reporting household incomes in the very low-income range.
Key Findings
The results showed equivalence between the two approaches across the 12-month program period. Both programs were based on Stanford's Active Choices physical activity counseling program. Participants receiving the Short Message Service (SMS)-based coaching through CareMessage increased their weekly walking by an average of 113.6 minutes (nearly 2 hours), while those receiving human telephone counseling increased walking by 116.4 minutes per week – a statistically equivalent difference of just 2.8 minutes.
Both groups achieved statistically significant improvements in physical activity that were sustained over the full 12-month study period. Additional benefits were observed in weight maintenance, reduced sedentary behavior, improved well-being, and increases in other types of physical activity beyond walking.
"This study represents a significant advancement in our understanding of how digital health tools can be leveraged to address health for all," said Dr. Abby C. King, lead author and professor in the Department of Epidemiology and Population Health and at the Stanford Prevention Research Center at Stanford University School of Medicine. "Achieving equivalent outcomes through an automated SMS system opens up tremendous possibilities for scaling effective interventions to larger populations while reducing the burden on healthcare systems."
The study utilized CareMessage's customizable and patented SMS platform to deliver a text-based version of Stanford's Active Choices telephone-based program. The system provided personalized coaching, goal-setting support, and interactive feedback tailored to each participant's needs and preferences. Participants in the SMS group received two to five text messages per week over 12 months, achieving a 94.1% response rate to interactive messages.
"This research validates what we've long believed – thoughtfully designed digital health interventions can deliver outcomes comparable to traditional human-delivered care," said Cecilia Corral, CareMessage Co-Founder and Chief Strategy Officer. "For Latino communities and other populations who face significant barriers to accessing traditional healthcare services, this represents a new opportunity for us to tackle preventive care and behavior change at scale."
Addressing Healthcare Accessibility Through Technology
The research addresses a critical gap in healthcare accessibility. While walking and similar physical activities provide numerous health benefits, particularly for aging inactive adults, many interventions are not accessible or culturally relevant for all populations. The study's focus on Latino adults, many of whom were low-income, demonstrates the potential for technology-enabled solutions to reach populations that have historically been underserved by traditional healthcare approaches.
About the Study
The randomized parallel group equivalence trial was designed to test intervention equivalence using a pre-specified margin of 30 minutes of walking per week. With an 88.9% completion rate (249 of 280 participants), the study demonstrated strong participant engagement across both intervention arms. The research utilized validated assessment tools, including the Community Healthy Activities Model Program for Seniors (CHAMPS) instrument and accelerometry to corroborate self-reported activity increases. Data analysis was performed from January 2023 through December 2024, with the research team taking a rigorous approach to ensure the reliability and validity of findings.
Clinical and Public Health Significance
The study's 12-month timeframe represents a longer intervention period than most mobile health studies to date, particularly for aging adults and Latino populations. Both programs also helped participants maintain stable weight throughout the study period, avoiding the typical yearly weight gain often observed in US adults.
Notably, the SMS intervention required substantially less participant time than human counseling while achieving equivalent results – a distinct advantage for working adults and healthcare systems seeking scalable solutions.
Implications for Digital Health
The publication in JAMA Network Open underscores the scientific rigor and significance of these findings. The research provides strong evidence that customizable SMS advising systems can produce meaningful, sustained improvements in physical activity for midlife and older adults from underserved communities.
These findings have broad implications for healthcare systems seeking alternative solutions to promote preventive care and chronic disease management among Latino and other underserved populations.
About CareMessage
CareMessage is a non-profit technology organization building the largest patient engagement platform for low-income populations in the United States. CareMessage delivers personalized health education and care coordination support via text messaging. Founded in 2012, the CareMessage platform has reached more than 20 million people across 45 U.S. states and territories, with a focus on addressing health disparities, improving health outcomes and increasing access to care for low-income communities. For more information, visit www.caremessage.org.
About the Department of Epidemiology & Population Health at Stanford University School of Medicine
Stanford Medicine's Department of Epidemiology and Population Health conducts research to understand the factors that shape health outcomes both nationally and globally. The department develops evidence-based strategies to improve health and wellbeing worldwide and trains future epidemiology and public health leaders.
Clinical Trial Registration: ClinicalTrials.gov Identifier: NCT02385591
SOURCE CareMessage
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