Late Breaking Abstract - Inhaled corticosteroids in bronchiectasis is associated to increased morbidity, Pseudomonas colonization and mortality – a five-year prospective cohort study

<b>Background and Objective:</b> Prescribing inhaled corticosteroids (ICS) for bronchiectasis (BE) is controversial, with current guidelines from the ERS recommending against a one-size fits all approach. Studies on the real-world ICS treatment prevalence and on the long-term effects on morbidity in bronchiectasis are lacking. <b>Methods:</b> This study comprises all patients with BE managed at outpatient clinics in two university hospitals in the Capital Region of Denmark between 2014-15. Demographics, co-diagnoses, lab and prescription data was acquired from patient journals. Patients were followed until April 2020. <b>Results:</b> Of 285 included patients, 131 (46%) of patients were prescribed ICS treatment. No difference in age, gender or smoking status was seen between ICS-treated and non-ICS-treated groups. At baseline, 18% of ICS treated patients had no concomitant diagnosis of asthma or COPD. At follow-up, this had increased to 23%. Patients prescribed ICS had a higher symptom burden in terms of cough (p 0.028), sputum production (p &lt;0.0001) and dyspnea (p &lt;0.0001). The relative risk of <i>Pseudomonas</i> positive sputum culture with ICS treatment was 1.21 (95% CI 1.01-1.44, p 0.045). ICS treatment was associated with increased risk of exacerbations requiring hospitalization (RR 1.91 (95% CI 1.27-2.87, p 0.0002) and the relative mortality risk with ICS treatment was 1.12 (95% CI 1.00-1.24, p 0.036). <b>Conclusions:</b> In this cohort, 23% of patients with BE were treated with ICS despite no underlying diagnosis of asthma or COPD. Overall, ICS treatment was associated with more severe exacerbations, risk of <i>Pseudomonas</i> colonization and higher mortality.