[1] Guys St Thomas NHS Fdn Trust, Sheffield, S Yorkshire, England
[2] Univ Coll London, Sheffield, S Yorkshire, England
[3] Royal Hallamshire Hosp, Sheffield S10 2JF, S Yorkshire, England
[4] Kings Coll Hosp London, London, England
[5] Univ Hertfordshire, Ctr Res Primary & Community Care, Hatfield AL10 9AB, Herts, England
[6] Univ Canarias, Tenerife, Spain
[7] Univ Barcelona, Barcelona, Spain
[8] Sahlgrens Univ Hosp, S-41345 Gothenburg, Sweden
[9] Radboud Univ Nijmegen, Med Ctr, NL-6525 ED Nijmegen, Netherlands
[10] Univ Hosp Maastricht, Maastricht, Netherlands