1. Department of Diabetes & Endocrinology, Hope Hospital, Salford, U.K
2. Medical Statistics Unit, Department of Mathematics and Statistics, Lancaster University, Lancaster, U.K
3. Wolfson Research Unit, School for Health, University of Durham, Stockton-on-Tees, U.K
4. Health Care Practice R&D Unit, University of Salford, Salford, U.K
5. School of Health Care Studies, University of Wales College of Medicine, Cardiff, U.K