Discipline of General Practice, Adelaide Medical School, The University of Adelaide, Level 1, Helen Mayo North, Frome Road, North Tce Campus, Adelaide, SA, 5005, Australia. nigel.stocks@adelaide.edu.au. Discipline of General Practice, Adelaide Medical School, The University of Adelaide, Level 1, Helen Mayo North, Frome Road, North Tce Campus, Adelaide, SA, 5005, Australia. Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, VIC, Australia. Berman Center for Outcomes and Clinical Research, Minneapolis Medical Research Foundation, Hennepin County Medical Center, Minneapolis, MN, USA. Department of Family Medicine and Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA. Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia. School of Public Health, Curtin University, Perth, WA, Australia. Department of Pharmacy Practice and Science, College of Pharmacy, Department of Family Medicine, Carver College of Medicine, University of Iowa, Iowa City, IA, USA.