[1] Univ Warwick, Warwick Clin Trials Unit, Coventry CV4 7AL, W Midlands, England
[2] Univ Aberdeen, Inst Appl Hlth Sci, Epidemiol Grp, Aberdeen AB25 2ZD, Scotland
[3] Univ Aberdeen, Inst Appl Hlth Sci, Med Stat Team, Aberdeen AB25 2ZD, Scotland
[4] Aston Univ, Sch Life & Hlth Sci, Birmingham B4 7ET, W Midlands, England
[5] Univ Aberdeen, Aberdeen Hlth Psychol Grp, Inst Appl Hlth Sci, Aberdeen AB25 2ZD, Scotland
[6] Univ Dundee, Dept Canc Nursing, Dundee DD1 4HJ, Scotland
[7] Univ Aberdeen, Div Appl Med, Co Director Inst Med Sci, Aberdeen AB25 2ZD, Scotland
[8] Ninewells Hosp & Med Sch, Dept Surg Oncol, Dundee Canc Ctr, Dundee DD1 9SY, Scotland