1. Wolfson Institute of Preventive MedicineQueen Mary University of London London UK
2. Section of Epidemiology and Biostatistics, School of Population HealthThe University of Auckland Auckland New Zealand
3. Faculty of Epidemiology & Population HealthLondon School of Hygiene and Tropical Medicine London UK
4. Applied Statistics in Medical Research GroupCatholic University of Murcia (UCAM) Murcia Spain
5. Population Health Research InstituteSt George's, University of London London UK