1Cigna, Global Wellbeing Solutions Ltd, 24 Southwark Bridge Road, London, SE1 9HF UK
2Population Health Research Institute, St George’s, University of London, London, UK
3Cigna Health and Life Insurance Company, Bloomfield, CT USA
4Department of Respiratory Medicine, The Whittington Hospital NHS Trust, Highgate Hill, London, N19 5NF UK JFIF d d Ducky d qhttp://ns.adobe.com/xap/1.0/