About the Authors
Division of Epidemiology, School of Public Health, University of California Berkeley, Berkeley, California, United States of America
Department of Medicine, Mahatma Gandhi Institute of Medical Sciences, Sevagram, Maharashtra, India
Montreal Chest Institute, McGill University, Montreal, Canada
The authors have declared that no competing interests exist.
RJ, AR, DM, and MP conceived and designed the study. RJ and MP collected, analyzed, and interpreted the data. RJ and MP drafted the manuscript. RJ, AR, DM, and MP performed critical revision of the manuscript.