Inhaled corticosteroids andStenotrophomonas maltophiliain outpatients with chronic obstructive pulmonary disease: a retrospective cohort study

Abstract

ObjectivesInhaled corticosteroids (ICS) are widely used in patients with chronic obstructive pulmonary disease (COPD). However, ICS are associated with an increased risk of adverse effects.We aimed to determine whether an association between a lower respiratory tract culture withStenotrophomonas maltophiliaand increasing ICS dosing in patients with COPD exists.DesignAn observational cohort study of outpatients with COPD in Denmark between 2010 and 2018.ICS exposure was categorised into four groups based on average daily consumption 1 year prior to inclusion: no use, low ICS dose (≤400 µg), moderate ICS dose (400–800 µg) and high ICS dose (>800 µg). Dose–response relationship was investigated by a multivariable Cox proportional hazards regression.ResultsOf the total 22 689 patients, 459 had lower respiratory tract cultures positive forS. maltophilia. The HR ofS. maltophiliaincreased with increasing daily ICS dose: low ICS dose HR 2.6 (95% CI 1.6 to 4.0), moderate ICS dose HR 3.0 (95% CI 1.9 to 4.6) and high ICS dose HR 5.7 (95% CI 3.8 to 8.5).ConclusionsWe found that ICS was associated with a high, dose-dependent increased hazard ofS. maltophiliain outpatients with COPD. High dose users had a nearly six times increased hazard compared with non-users of ICS. When appropriate, attempts at de-escalating ICS treatment should be made.