LLM-driven text-based coaching prompts grounded in the Transtheoretical Model of Change increase daily step count compared to generic prompts in adults at risk for cardiovascular disease.
The My Heart Counts study is a prospective observational cohort with an embedded randomized crossover trial (N=15,000) evaluating personalized LLM-generated coaching prompts versus generic prompts. The primary endpoint is change in daily step count, analyzed using mixed-effects models.
This article is automatically generated from the structured evidence profile behind the claim above. Scores reflect the quality and quantity of available research, not clinical advice.
LLM-driven text-based coaching prompts grounded in the Transtheoretical Model of Change increase daily step count compared to generic prompts in adults at risk for cardiovascular disease. The current body of evidence comprises 1 study, including 1 randomized controlled trial. EvidenceHub rates the overall confidence at 42/100 (low).
The Claim
LLM-driven text-based coaching prompts grounded in the Transtheoretical Model of Change increase daily step count compared to generic prompts in adults at risk for cardiovascular disease.
This conclusion is most relevant to: Adults (N=15,000) across the United States and United Kingdom.
What the Research Shows
The conclusion draws on 1 linked study. Highlights from the cited literature:
- ▸Design and rationale of the my heart counts cardiovascular health study: a large-scale, fully digital biobank, and randomized trial of large language model-driven coaching of physical activity. (American journal of preventive cardiology, 2026) —
How It Works
The proposed biological pathway:
- ▸LLM generates personalized coaching prompts based on Transtheoretical Model of Change
- ▸Prompts are delivered via smartphone application
- ▸Participants receive prompts during intervention weeks in crossover design
- ▸Result: Change in daily step count compared to generic prompts
Who Might Benefit
Evidence fit by population:
- ▸Adults (N=15,000) across the United States and United Kingdom
Recommended Dose
N/A
Limitations & Caveats
Important context when interpreting this evidence:
- ▸Results are not yet available as recruitment commenced in March 2026 and is ongoing
- ▸Platform exclusivity (iOS only initially, Android planned for 2027) may limit generalizability
- ▸Reliance on smartphone-based passive data collection may introduce selection bias toward tech-savvy individuals
Frequently Asked Questions
What is the primary outcome of the My Heart Counts trial?▼
The primary outcome is the change in daily step count between LLM-driven and generic text-based intervention arms.
How many participants are enrolled in this study?▼
The target enrollment is 15,000 adults across the United States and United Kingdom.
What is the intervention being tested?▼
The intervention is personalized text-based coaching prompts generated by a large language model (LLM) grounded in the Transtheoretical Model of Change, compared to generic prompts.
When did recruitment for this study begin?▼
Recruitment commenced in March 2026 and is ongoing.
References
- 1.Schmiedmayer P, Johnson A, Schuetz N, Kollmer L, Goldschmidt P, Delgado-SanMartin J, Zhang KW, Mantena SD, Tolas A, Montalvo S, Ramirez-Posada M, O'Sullivan JW, Oppezzo M, King AC, Rodriguez F, Ashley E, Lawrie A, Kim DS. “Design and rationale of the my heart counts cardiovascular health study: a large-scale, fully digital biobank, and randomized trial of large language model-driven coaching of physical activity..” American journal of preventive cardiology, 2026. PMID: 42395096 DOI: 10.1016/j.ajpc.2026.101565