IV-treated pulmonary exacerbations in the prior year: An important independent risk factor for future pulmonary exacerbation in cystic fibrosis

Background: Single-center analyses have suggested that the number of CF pulmonary exacerbations (PEx) treated with intravenous antibiotics an individual has experienced in the prior year is significantly associated with their future PEx hazard. Methods: We studied Prior-year PEx association with future PEx hazard by Cox proportional hazards regression among CF Foundation Patient Registry patients who experienced PEx after Jan 1, 2010. Results: Among 13,579 patients, those with 1, 2, 3, or >= 4 Prior-year PEx treated with intravenous antibiotics were at 1.8, 2.9, 4.8, and 8.7 higher PEx hazard vs those without (P < .0001). Adjustment with significant demographic and clinical covariates (univariate P <=.0001) reduced Prior year PEx hazard ratios to 1.6, 2.4, 3.6, and 6.0 (P < .0001). No other covariates had adjusted hazard ratios of >1.7. Conclusions: Prior-year PEx strongly associate with future PEx hazard and should be accounted for in prospective trials where treatment associated change in PEx hazard is an efficacy outcome. (C) 2016 The Authors. Published by Elsevier B.V. on behalf of European Cystic Fibrosis Society.