Asthma exacerbations in a tertiary hospital: clinical features, triggers, and risk factors for hospitalization.

BACKGROUND Risk factors for asthma exacerbations are not fully understood. The aim of this study was to determine the epidemiological and clinical characteristics of patients with an asthma exacerbation, potential triggers, and possible predictors of hospitalization. METHODS A retrospective, non-interventional cohort study was conducted in adult patients who attended the Emergency Department of a tertiary hospital with an asthma exacerbation during 2014. RESULTS 831 patients (888 events) were included. The highest number of episodes occurred in January and May. Respiratory infection was considered the trigger in 523 events. 34.21% had ≥260 eosinophils/mm3 (20.7%≥400 eosinophils/mm3), significantly associated with allergic asthma (p<0.0001). Risk factors for hospitalization were: older age [OR:1.58 (95% CI 1.46-1.71)]; no previous diagnosis of asthma [OR:1.40(95% CI 1.06-1.86)]; poorly controlled asthma[OR:1.78 (95% CI 1.10-2.88)]; respiratory infection [OR:2.65 (95% CI 1.95-3.62)]; and severe crisis with more treatment requirements. Of those asthmatics with ≥400 eosinophils/mm3, the rate of hospitalization was lower (p<0.001). CONCLUSION Older age, absence of a previous asthma diagnosis, uncontrolled disease or concomitant COPD are frequent among patients presenting to the ED with asthma exacerbations. There were some features associated with higher risk of admission. Blood eosinophilia should be considered as a marker of asthma, but not as a predictor of hospitalization.