AUTHOR=Graham Dan J. TITLE=Frontiers Commentary: The HEART Mobile Phone Trial: The Partial Mediating Effects of Self-Efficacy on Physical Activity among Cardiac Patients JOURNAL=Frontiers in Public Health VOLUME=4 YEAR=2016 URL=https://www.frontiersin.org/articles/10.3389/fpubh.2016.00066 DOI=10.3389/fpubh.2016.00066 ISSN=2296-2565