[1] Univ Bath, Pharm & Pharmacol, Bath BA2 7AY, Avon, England
[2] Royal Natl Hosp Rheumat Dis, Rheumatol, Upper Borough Walls, Bath BA1 1RL, Avon, England
[3] Royal United Hosp, Bath BA1 3NG, Avon, England
[4] Univ Manchester, Arthrit Res UK Ctr Epidemiol, Manchester, Lancs, England
[5] Univ Bath, Math Sci, Bath BA2 7AY, Avon, England