Title: Community determinants of COPD exacerbations in elderly patients in Poland: protocol for a retrospective big data observational cohort study
Authors: Izabela Żakowaska, Katarzyna Kosiek, Anna Kowalczyk, Jacek Grabowski, Maciek Godycki-Ćwirko
Journal: BMJ Open
Publication type: article
DOI: 10.1136/bmjopen-2019-030524