[1] Univ Edinburgh, Usher Inst Populat Hlth Sci & Informat, Edinburgh, Midlothian, Scotland
[2] Univ Exeter, Med Sch, Exeter, Devon, England
[3] Royal Devon & Exeter Hosp, Blood Sci, Exeter, Devon, England
[4] Univ Edinburgh, Inst Genet & Mol Med, Edinburgh, Midlothian, Scotland
[5] NHS Fife, Dept Publ Hlth, Kirkcaldy, Scotland