William Bird1,2,3, Giovanna Adamo4, Erica Pitini4, Muir Gray5, Anant Jani5. 1. European Centre for Environment and Human Health, University of Exeter Medical School, Cornwall TR1 3HD, UK. 2. Intelligent Health Ltd, Reading RG6 6BU, UK. 3. Berkshire Healthcare NHS Foundation Trust, Bracknell RG12 1BQ, UK. 4. Dipartimento di Sanita Pubblica e Malattie Infettive, Universita degli Studi di Roma La Sapienza, Roma 00185, Italy. 5. Value Based Healthcare Programme - Department of Primary Care, University of Oxford, Oxford OX2 6GG, UK.