Prevalence of chronic obstructive pulmonary disease and associated risk factors in Uganda (FRESH AIR Uganda): a prospective cross-sectional observational study oleh Frederik van Gemert, MD, Bruce Kirenga, MMED, Niels Chavannes, PhD, Prof. Moses Kamya, PhD, Simon Luzige, MMED, Patrick Musinguzi, MMED, John Turyagaruka, MPH, Rupert Jones, MD, Ioanna Tsiligianni, PhD, Sian Williams, MSc, Corina de Jong, PhD, Prof. Thys van der Molen, PhD