Graphical Abstract
We thank Drs Yang and Zhao for their thoughtful letters regarding our recent paper describing the primary results of the ALLSTAR (RCT of Strategies to Augment Physical Activity in Black and Hispanic Breast and Prostate Cancer Survivors) trial comparing behaviorally designed gamification vs attention control to increase physical activity in Black and Hispanic breast and prostate cancer survivors.1 We appreciate the opportunity to clarify several important points.
We agree with Dr Zhao’s description of the intervention’s key advantages, including scalability, capacity for integration into the health care system, and the use of personalized goal setting. Dr Zhao also notes that the trial was limited by its exclusion of speakers of languages other than English or Spanish and the predominant enrollment of breast cancer survivors. The patients enrolled in our study were representative of the communities our centers serve, and we agree with Dr Zhao that the intervention should be tested in other cancer populations. Our intervention’s simplicity and scalability using the Way to Health platform should facilitate this testing.
We also agree with Dr Yang’s points, including attenuation of treatment effect during follow-up, the lack of a dedicated economic analysis, and the use of mean daily steps as the trial’s primary outcome rather than a more established cardiovascular risk marker. However, it is important to consider ALLSTAR in context. ALLSTAR is the sixth randomized clinical trial of a gamification intervention to increase physical activity in patients at elevated cardiovascular risk to report change from baseline in daily steps vs attention control across both intervention and postintervention follow-up periods (Figure 1). In all these trials, there was attenuation of treatment effect over the duration of the intervention, but when pooling estimates across trials, gamification still increased mean daily step count by 687 steps/day (95% CI: 491-883 steps/day) over the intervention period and 543 steps/day (95% CI: 314-773 steps/day) over postintervention follow-up. Furthermore, increases in mean daily step count with gamification came on top of increases in attention control arms, which included goal setting and daily text messages, and increased daily step count by nearly 1,000 steps/day from baseline. In all trials, the decline in mean daily step counts from their peak at the start of the intervention period approximates an exponential decay curve, with a steep initial decline followed by flattening at a level that remains substantially greater than participants’ baseline as well as attention control.
Figure 1.
The Effect of Gamification on Daily Step Count Over Intervention and Postintervention Follow-Up Periods
Pooling estimates from 6 clinical trials in adults at high cardiovascular risk, gamification increased mean daily step count by 687 steps/day (95% CI: 491-883 steps/day) over the intervention period and 543 steps/day (95% CI: 314-773 steps/day) over postintervention follow-up vs attention control.
Dr Yang is also correct in noting that dedicated health economic analyses are needed prior to policy adoption. In a formal economic analysis of a closely related gamification intervention in the BE ACTIVE (Behavioral Economic Approaches to Increase Physical Activity Among Patients With Elevated Risk for Cardiovascular Disease) randomized controlled trial, gamification was highly cost effective per American College of Cardiology/American Heart Association guidelines (< $50,000 per life-year gained) across a range of assumptions regarding the attenuation of treatment effect over time.2,3
However, these analyses necessarily relied on assumptions about the effect of increasing physical activity on cardiovascular events. Although a robust body of observational literature consistently demonstrates associations between higher daily step count and lower incidence of mortality and cardiovascular events,4 and clinical trials have shown that physical activity programs reduce mortality and cardiovascular events, including in patients with cancer,5 whether a scalable, home-based program designed to increase step count reduces cardiovascular events or improves established markers of cardiovascular risk is uncertain and must be tested in adequately powered clinical trials.
Footnotes
Ronald Witteles, MD, Deputy Editor, served as Acting Editor-in-Chief for this paper.
Dr Volpp is a co-owner of a behavioral economics consulting firm, VAL Health; and is a member of the scientific advisory board of THRIVE Global. Neither organization has any involvement in this study. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
The authors attest they are in compliance with human studies committees and animal welfare regulations of the authors’ institutions and Food and Drug Administration guidelines, including patient consent where appropriate. For more information, visit the Author Center.
References
- 1.Fanaroff A.C., Orr J.A., Anucha C., et al. Behaviorally designed gamification and physical activity among breast and prostate cancer survivors. JACC CardioOncol. 2025;7(7):816–828. doi: 10.1016/j.jaccao.2025.10.001. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Anderson J.L., Heidenreich P.A., Barnett P.G., et al. ACC/AHA statement on cost/value methodology in clinical practice guidelines and performance measures: a report of the American College of Cardiology/American Heart Association Task Force on Performance Measures and Task Force on Practice Guidelines. J Am Coll Cardiol. 2014;63(21):2304–2322. doi: 10.1016/j.jacc.2014.03.016. [DOI] [PubMed] [Google Scholar]
- 3.Russell L.B., Volpp K.G.M., Patel M.S., et al. Cost-effectiveness of gamification, financial incentives, or both to increase physical activity among patients with elevated risk for cardiovascular disease. Circ Cardiovasc Qual Outcomes. 2025;18(7) doi: 10.1161/CIRCOUTCOMES.124.011839. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.del Pozo Cruz B., Ahmadi M.N., Lee I.M., Stamatakis E. Prospective associations of daily step counts and intensity with cancer and cardiovascular disease incidence and mortality and all-cause mortality. JAMA Intern Med. 2022;182(11):1139–1148. doi: 10.1001/jamainternmed.2022.4000. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Courneya K.S., Vardy J.L., O’Callaghan C.J., et al. Structured exercise after adjuvant chemotherapy for colon cancer. N Engl J Med. 2025;393(1):13–25. doi: 10.1056/NEJMoa2502760. [DOI] [PubMed] [Google Scholar]