1. ISGlobal, Barcelona, Spain, CIBER Epidemiologia y Salud Publica (CIBERSP), Barcelona, Spain, Universitat Pompeu Fabra, Barcelona, Spain
2. Division of Pulmonary Medicine, Charnock Hospital, Kolkata, India, Department of Pneumology, Allergy & Asthma Research Centre, Kolkata, India
3. Department of Statistics, Presidency University, Kolkata, India
4. Division of Pulmonary Medicine, Charnock Hospital, Kolkata, India
5. Department of Respiratory Medicine, Rabindranath Tagore International Institute of Cardiac Sciences, Kolkata, India
6. Department of Pulmonary Medicine, Institute of Post Graduate Medical Education & Research and SSKM Hospital, Kolkata, India
7. Department of Medicine, University of Perugia, Perugia, Italy
8. National Heart and Lung Institute, Imperial College London, London, UK, , Email: subhabrata2207@gmail.com