Frequency and severity of COPD exacerbations and future risk of exacerbations and mortality: an observational cohort study in Canada

OBJECTIVES: To estimate the risk of subsequent exacerbations, in relation to history of exacerbations, in a cohort of older chronic obstructive pulmonary disease (COPD) patients in Canada. METHODS: Using provincial claims data from Ontario, Canada, patients with COPD aged≥65 years (identified between 2004 and 2018; followed up to 2020) were categorised into one of four mutually exclusive groups: no exacerbation; only one moderate; only one …