1 Health Services Research Unit, University of Aberdeen, Aberdeen, UK. k.gillies@abdn.ac.uk.
2 Clinical Epidemiology Program, Ottawa Hospital Research Institute (OHRI), The Ottawa Hospital, General Campus, 501 Smyth Rd, Ottawa, ON, K1H 8L6, Canada.
3 School of Epidemiology and Public Health, University of Ottawa, Ottawa, ON, K1G 5Z3, Canada.
4 Health Services Research Unit, University of Aberdeen, Aberdeen, UK.
5 Melbourne School of Health Sciences, University of Melbourne, Melbourne, Australia.
6 Harvard Center for Bioethics, Harvard University, Boston, USA.
7 Prism Analytic Technologies, Cambridge, MA, USA.
8 Departments of Medicine, Epidemiology & Biostatistics, and Philosophy, Western University, London, Ontario, Canada.