1 Respiratory Science, University of Leicester, Leicester, UK; Centre for Exercise and Rehabilitation Science, University Hospitals Leicester NHS Trust, Leicester LE3 9QP, UK. Electronic address: sally.singh@uhl-tr.nhs.uk.
2 University of Exeter Medical School, College of Medicine and Health, University of Exeter, Exeter, UK.
3 Chest Research Foundation, Pune, India.
4 Population Studies and Clinical Trials, Makerere Lung Institute, Makerere University College of Health Sciences, Mulago Hospital, Kampala, Uganda.
5 Liverpool School of Tropical Medicine, Liverpool, UK.