[1] Univ Aberdeen, Sch Med & Dent, Dept Obstet & Gynaecol, Div Appl Hlth Sci, Aberdeen AB25 2ZD, Scotland
[2] Univ Aberdeen, Div Med & Dent Educ, Aberdeen AB25 2ZD, Scotland
[3] Univ Dundee, Dept Publ Hlth & Primary Care, Dundee, Scotland
[4] Aberdeen Royal Infirm, Dept Haematol, Anchor Unit, NHS Grampian, Aberdeen, Scotland
[5] Aberdeen Royal Infirm, Dept Oncol, Anchor Unit, NHS Grampian, Aberdeen, Scotland
[6] Royal Aberdeen Childrens Hosp, NHS Grampian, Aberdeen, Scotland