Adherence to a Digital Therapeutic Mediates the Relationship Between Momentary Self-Regulation and Health Risk Behaviors

Enzo G Plaitano ^1,2* Daniel McNeish ³ Sophia Bartels ⁴ Kathleen Bell ¹ Jesse Dallery ⁵ Michael Grabinski ¹ Michaela Kiernan ⁶ Hannah A Lavoie ⁷ Shea M Lemley ¹ Michael R Lowe ⁸ David P MacKinnon ³ Stephen A. Metcalf ^1,9 Lisa Onken ¹⁰ Judith J Prochaska ⁶ Cady L Sand ^1,11 Emily A Scherer ¹ Luke E Stoeckel ¹⁰ Haiyi Xie ¹ Lisa A Marsch ¹

• ¹ Center for Technology and Behavioral Health, Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire, United States
• ² The Dartmouth Institute for Health Policy and Clinical Practice, Dartmouth College, Lebanon, New Hampshire, United States
• ³ Department of Psychology, Arizona State University, Tempe, Arizona, United States
• ⁴ Department of Health Behavior, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
• ⁵ Department of Psychology, University of Florida, Gainesville, Florida, United States
• ⁶ Stanford Prevention Research Center, Stanford University, Stanford, California, United States
• ⁷ Department of Health Education and Behavior, University of Florida, Gainesville, Florida, United States
• ⁸ Department of Psychological and Brain Sciences, Drexel University, Philadelphia, Pennsylvania, United States
• ⁹ Department of Public Health and Primary Care, University of Cambridge, Cambridge, England, United Kingdom
• ¹⁰ National Institute on Aging (NIH), Bethesda, Maryland, United States
• ¹¹ Apple (United States), Cupertino, California, United States

Introduction: Smoking, obesity, and insufficient physical activity are modifiable health risk behaviors. Self-regulation is one fundamental behavior change mechanism often incorporated within digital therapeutics as it varies momentarily across time and contexts and may play a causal role in improving these health behaviors. However, the role of momentary self-regulation in achieving behavior change has been infrequently examined. Using a novel momentary self-regulation scale, this study examined how targeting self-regulation through a digital therapeutic impacts adherence to the therapeutic and two different health risk behavioral outcomes. Methods: This prospective interventional study included momentary data for 28 days from 50 participants with obesity and binge eating disorder and 50 participants who smoked regularly. An evidence-based digital therapeutic, called Laddr™, provided self-regulation behavior change tools. Participants reported on their momentary self-regulation via ecological momentary assessments and health risk behaviors were measured as steps taken from a physical activity tracker and breathalyzed carbon monoxide. Medical regimen adherence was assessed as daily Laddr usage. Bayesian dynamic mediation models were used to examine moment-to-moment mediation effects between momentary self-regulation subscales, medical regimen adherence, and behavioral outcomes. Results: In the binge eating disorder sample, the perseverance (β1= 0.17, 95% CI = [0.06, 0.45]) and emotion regulation (β1= 0.12, 95% CI = [0.03, 0.27]) targets of momentary self-regulation positively predicted Laddr adherence on the following day, and higher Laddr adherence was subsequently a positive predictor of steps taken the same day for both perseverance (β2= 0.335, 95% CI = [0.030, 0.717]) and emotion regulation (β2= 0.389, 95% CI = [0.080, 0.738]). In the smoking sample, the perseverance target of momentary self-regulation positively predicted Laddr adherence on the following day (β= 0.91, 95% CI = [0.60, 1.24]). However, higher Laddr adherence was not a predictor of CO values on the same day (β2 = -0.09, 95% CI = [-0.24, 0.09]). Conclusions: This study provides evidence that a digital therapeutic targeting self-regulation can modify the relationships between momentary self-regulation, medical regimen adherence, and behavioral health outcomes. Together, this work demonstrated the ability to digitally assess the transdiagnostic mediating effect of momentary self-regulation on medical regimen adherence and pro-health behavioral outcomes.