| Affiliation: | 1. Department of Health Services Research and Policy, London School of Hygiene and Tropical Medicine, 15-17 Tavistock Place, London WC1H 9SH, UK;2. Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK;3. Statistics Modelling and Economics Department, Health Protection Directorate, Public Health England, London NW9 5EQ, UK;4. Department of Primary Care and Public Health, School of Public Health, Imperial College, London W6 8RP, UK |
