[1] Univ Hosp Bristol & Weston NHS Fdn Trust, Natl Inst Hlth Res Appl Res Collaborat West NIHR, Bristol, Avon, England
[2] Univ Bristol, Populat Hlth Sci, Bristol, Avon, England
[3] Univ Bristol, Bristol Trials Ctr, Clin Trials & Evaluat Unit, Bristol, Avon, England
[4] Bristol Heart Inst, Dept Cardiol, Bristol, Avon, England