1. University of Bristol; Population Health Sciences, Bristol Medical School; 39 Whatley Road Bristol UK BS8 2PS
2. School of Medicine, Cardiff University; DECIPHer (Centre for the Development and Evaluation of Complex Interventions for Public Health Improvement), Centre for Trials Research; 4th Floor Neuadd Meirionnydd Cardiff UK CF14 4YS
3. University of Adelaide; School of Public Health; Level 7, 178 North Terrace, Mail Drop DX 650 550 Adelaide South Australia Australia 5005
4. Newcastle University; Institute of Health and Society; Baddiley-Clark Building, Richardson Road Newcastle Upon Tyne UK NE2 4AX
5. University of Texas; Department of Kinesiology and Health Education; 1 University Station, D3700 Austin Texas USA 78712