1 Centre for Primary Care and Health Services Research, Division of Population Health, Health Services Research and Primary Care, School of Health Sciences, The University of Manchester, Manchester, UK.
2 Centre for Primary Care and Health Services Research, Division of Population Health, Health Services Research and Primary Care, School of Health Sciences, The University of Manchester, Manchester, UK; Division of Informatics, Imaging and Data Sciences, School of Health Sciences, The University of Manchester, Manchester, United Kingdom.
3 Keele Cardiovascular Research Group, Centre for Prognosis Research, School of Medicine, Keele University, Stoke-on-Trent, United Kingdom. Electronic address: mamasmamas1@yahoo.co.uk.