1. Department of Physical Medicine and Rehabilitation, University of Kinshasa, Kinshasa, The Democratic Republic of the Congo,
2. Department of Respiratory Sciences, University of Leicester, Leicester, United Kingdom,
3. Lung Health Group, Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Queen Elizabeth Central Hospital, Blantyre, Malawi,
4. Department of Medicine, Makerere University Lung Institute, Makerere University Lung Institute, Kampala, Uganda,