Published on in Vol 19, No 6 (2017): June
1 Centre for Behaviour Change, Department of Clinical, Educational and Health Psychology, University College London, London, United Kingdom
2 Department of Psychology, University of Southampton, Southampton, United Kingdom
3 Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, United Kingdom
4 Health Behaviour Research Centre, University College London, United Kingdom
5 Department of Family Medicine and Public Health, The Qualcomm Institute - Calit2, University of California, San Diego, CA, United States
6 The Center for Wireless and Population Health Systems, The Qualcomm Institute - Calit2, University of California, San Diego, CA, United States
7 Public Health England, Skipton House, London, United Kingdom
8 Department of Primary Care and Public Health, Imperial College London, London, United Kingdom