[1] Univ Oxford, Wellcome Ctr Eth & Humanities, Oxford, England
[2] Univ Oxford, Nuffield Dept Populat Hlth, Ethox Ctr, Oxford, England
[3] Norwegian Univ Sci & Technol, Dept Publ Hlth & Gen Practice, Trondheim, Norway
[4] Univ Helsinki, Fac Social Sci, Helsinki, Finland
[5] Univ Helsinki, Helsinki Coll Adv Studies, Helsinki, Finland
[6] Univ Oxford, Nuffield Dept Populat Hlth, Oxford OX1 2JD, England
[7] Univ Oxford, NIHR Oxford Biomed Res Ctr, Oxford, England
[8] Univ Helsinki, Ctr Populat Hlth & Soc, Helsinki, Finland
[9] Open Univ, Milton Keynes, Bucks, England