[1] Univ Warwick, Warwick Med Sch, Warwick Appl Hlth, Gibbet Hill, Coventry CV4 7AL, England
[2] Univ Oxford, Nuffield Dept Primary Care Hlth Sci, Oxford, England
[3] Univ Amsterdam, Anthropol Dept, Amsterdam, Netherlands
[4] Univ Oxford, Nuffield Dept Primary Care Hlth Sci, Med Sociol, Oxford, England
[5] Univ Southampton, Primary Care Populat Sci & Med Educ, Southampton, England