Testing the Effects of App-Based Motivational Messages on Physical Activity and Resting Heart Rate Through Smartphone App Compliance in Patients With Vulnerable Coronary Artery Plaques: Protocol for a Microrandomized Trial

Sayan Mitra; Cynthia M Kroeger; Jing Xu; Leah Avery; Andrius Masedunskas; Sophie Cassidy; Tian Wang; Imre Hunyor; Ian Wilcox; Robin Huang; Bibhas Chakraborty; Luigi Fontana

doi:10.2196/46082

Testing the Effects of App-Based Motivational Messages on Physical Activity and Resting Heart Rate Through Smartphone App Compliance in Patients With Vulnerable Coronary Artery Plaques: Protocol for a Microrandomized Trial

JMIR Res Protoc. 2023 Oct 2:12:e46082. doi: 10.2196/46082.

Authors

Sayan Mitra^{1

2}, Cynthia M Kroeger^{1

2}, Jing Xu^{3

4

5}, Leah Avery⁶, Andrius Masedunskas^{1

2}, Sophie Cassidy^{1

2}, Tian Wang^{1

2}, Imre Hunyor^{1

7

8}, Ian Wilcox^{1

7

8}, Robin Huang⁹, Bibhas Chakraborty^{4

5

10

11}, Luigi Fontana^{1

2

12

13}

Affiliations

¹ Central Clinical School, Faculty of Medicine and Health, The University of Sydney, Camperdown, Australia.
² Charles Perkins Centre, The University of Sydney, Camperdown, Australia.
³ Office of Education, Duke-National University of Singapore Medical School, Singapore, Singapore.
⁴ Program in Health Services and Systems Research, Duke-National University of Singapore Medical School, Singapore, Singapore.
⁵ Centre for Quantitative Medicine, Duke-National University of Singapore Medical School, Singapore, Singapore.
⁶ School of Health & Life Sciences, Teesside University, Tees Valley, England, United Kingdom.
⁷ Department of Cardiology, Royal Prince Alfred Hospital, Sydney, Australia.
⁸ Central Sydney Cardiology, Royal Prince Alfred Medical Centre, Sydney, Australia.
⁹ School of Computer Science, The University of Sydney, Darlington, Australia.
¹⁰ Department of Statistics and Data Science, National University of Singapore, Singapore, Singapore.
¹¹ Department of Biostatistics and Bioinformatics, Duke University, Durham, NC, United States.
¹² Department of Endocrinology, Royal Prince Alfred Hospital, Sydney, Australia.
¹³ Department of Clinical and Experimental Sciences, Brescia University, Brescia, Italy.

PMID: 37782531
PMCID: PMC10580140
DOI: 10.2196/46082

Abstract

Background: Achieving the weekly physical activity recommendations of at least 150-300 minutes of moderate-intensity or 75-150 minutes of vigorous-intensity aerobic exercise is important for reducing cardiometabolic risk, but evidence shows that most people struggle to meet these goals, particularly in the mid to long term.

Objective: The Messages Improving Resting Heart Health (MIRTH) study aims to determine if (1) sending daily motivational messages through a research app is effective in improving motivation and in promoting adherence to physical activity recommendations in men and women with coronary heart disease randomized to a 12-month intensive lifestyle intervention, and (2) the time of the day when the message is delivered impacts compliance with exercise training.

Methods: We will conduct a single-center, microrandomized trial. Participants will be randomized daily to either receive or not receive motivational messages over two 90-day periods at the beginning (phase 1: months 4-6) and at the end (phase 2: months 10-12) of the Lifestyle Vulnerable Plaque Study. Wrist-worn devices (Fitbit Inspire 2) and Bluetooth pairing with smartphones will be used to passively collect data for proximal (ie, physical activity duration, steps walked, and heart rate within 180 minutes of receiving messages) and distal (ie, change values for resting heart rate and total steps walked within and across both phases 1 and 2 of the trial) outcomes. Participants will be recruited from a large academic cardiology office practice (Central Sydney Cardiology) and the Royal Prince Alfred Hospital Departments of Cardiology and Radiology. All clinical investigations will be undertaken at the Charles Perkins Centre Royal Prince Alfred clinic. Individuals aged 18-80 years (n=58) with stable coronary heart disease who have low attenuation plaques based on a coronary computed tomography angiography within the past 3 months and have been randomized to an intensive lifestyle intervention program will be included in MIRTH.

Results: The Lifestyle Vulnerable Plaque Study was funded in 2020 and started enrolling participants in February 2022. Recruitment for MIRTH commenced in November 2022. As of September 2023, 2 participants were enrolled in the MIRTH study and provided baseline data.

Conclusions: This MIRTH microrandomized trial will represent the single most detailed and integrated analysis of the effects of a comprehensive lifestyle intervention delivered through a customized mobile health app on smart devices on time-based motivational messaging for patients with coronary heart disease. This study will also help inform future studies optimizing for just-in-time adaptive interventions.

Trial registration: Australian New Zealand Clinical Trials Registry ACTRN12622000731796; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=382861.

International registered report identifier (irrid): DERR1-10.2196/46082.

Keywords: adherence; coronary artery disease; coronary heart disease; digital health; health behavior; heart rate; messages; mhealth; microrandomized trial; mobile app; physical activity; smartphone; telehealth; user motivation.

©Sayan Mitra, Cynthia M Kroeger, Jing Xu, Leah Avery, Andrius Masedunskas, Sophie Cassidy, Tian Wang, Imre Hunyor, Ian Wilcox, Robin Huang, Bibhas Chakraborty, Luigi Fontana. Originally published in JMIR Research Protocols (https://www.researchprotocols.org), 02.10.2023.