This study aims to (1) iteratively develop and program a theoretically informed technology-based nudge message library for a diverse patient population using multiple and iterative N of 1 within subject studies. Investigators will also engage patient, provider and health systems stakeholders in designing and refining the messages. (2)Develop a one-page decision aid tool to present information designed with principles of shared decision making including pros and cons of hospital and home-based rehabilitation. Investigators will engage patients, providers, and health systems stakeholders to provide feedback on the information sheet. (3) Conduct a 2x2 factorial design randomized trial of a) choice and b) nudge messaging to improve primary outcome of CR adherence. Secondary outcomes will include enrollment and completion of CR, exercise capacity, patient engagement, quality of life, hospitalizations, and healthcare utilization. The study will additionally evaluate the interventions using a mixed methods approach applying the RE-AIM (reach, effectiveness, adoption, implementation, and maintenance) framework and a cost-effectiveness analysis. The cost-effectiveness analysis sub-study will evaluate the implementation cost of home-based and hospital-based cardiac rehabilitation programs in addition to the incremental cost effectiveness ratios for each intervention.
