[1] Imperial Coll Healthcare NHS Trust, Dept Urol, London W2 1NY, England
[2] Univ Aberdeen, Ctr Healthcare Randomised Trials, Hlth Sci Bldg,Foresterhill, Aberdeen, Scotland
[3] Univ Aberdeen, Hlth Serv Res Unit, Hlth Sci Bldg,Foresterhill, Aberdeen, Scotland
[4] Univ Aberdeen, Hlth Econ Res Unit, Aberdeen, Scotland
[5] Aberdeen Royal Infirm, Dept Urol, NHS Grampian, Aberdeen, Scotland
[6] Univ Edinburgh, Usher Inst Populat Hlth Sci & Informat, Edinburgh Clin Trials Unit, Edinburgh, Midlothian, Scotland
[7] St Georges Univ Hosp NHS Fdn Trust, Dept Urol, London, England
[8] Norfolk & Norwich Univ Hosp NHS Fdn Trust, Dept Urol, Norwich, Norfolk, England
[9] British Assoc Urol Surg, Sect Endourol, Stone Patient Advisory Grp, London, England
[10] North Bristol NHS Trust, Bristol Urol Inst, Bristol, Avon, England
[11] Univ Aberdeen, Acad Urol Unit, Hlth Sci Bldg,Foresterhill, Aberdeen, Scotland
[12] Univ Nottingham, Nottingham Clin Trials Unit, Univ Pk, Nottingham, England