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   ^{1, 2} , MBBS, MPH ;   Cynthia M Kroeger   ^{1, 2} , PhD ;   Jing Xu   ^{3, 4, 5} , PhD ;   Leah Avery   ⁶ , MSc, PhD ;   Andrius Masedunskas   ^{1, 2} , PhD ;   Sophie Cassidy   ^{1, 2} , MSc, PhD ;   Tian Wang   ^{1, 2} , MND ;   Imre Hunyor   ^{1, 7, 8} , MBBS (Hons), DPhil ;   Ian Wilcox   ^{1, 7, 8} , MBBS, PhD ;   Robin Huang   ⁹ , MPhil ;   Bibhas Chakraborty   ^{4, 5, 10, 11} , MStat, PhD ;   Luigi Fontana   ^{1, 2, 12, 13} , MD, PhD

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