[1] Univ Aberdeen, Hlth Econ Res Unit, Foresterhill, Aberdeen, Scotland
[2] Gen Sir John Kotelawala Def Univ, Fac Med, Colombo, Sri Lanka
[3] Imperial Coll London, Dept Metab Digest & Reprod, London, England
[4] Univ Aberdeen, Hlth Serv Res Unit, Aberdeen, Scotland
[5] Univ Newcastle Tyne, Translat & Clin Res Inst, Newcastle Upon Tyne, England
[6] Newcastle Tyne Hosp NHS Fdn Trust, Dept Endocrinol, Newcastle Upon Tyne, England
[7] Univ Aberdeen, Sch Med Med Sci & Nutr, Foresterhill, Aberdeen, Scotland
[8] Univ Aberdeen, Hlth Econ Res Unit, Foresterhill, Aberdeen AB25 2ZD, Scotland
[9] Imperial Coll London, Hammersmith Hosp, Fac Med, 6th Floor Commonwealth Bldg, London W12 0NN, England