Daniel O Obaseki1, Njira L Lugogo2, Sonia A Buist3. 1. 1 Department of Medicine, Obafemi Awolowo University, Ile-Ife, Nigeria. 2. 2 Division of Pulmonary and Critical Care Medicine, Duke University Hospital, Durham, North Carolina; and. 3. 3 Division of Pulmonary and Critical Care Medicine, Oregon Health and Sciences University, Portland, Oregon.