Wiebke Bartels, Simon Adamson, Lisa Leung, Don D Sin, Stephan F van Eeden

Readmissions are common following acute exacerbations of chronic obstructive pulmonary disease (AECOPD) and are partially responsible for increased morbidity and mortality in COPD. Numerous factors have been shown to predict readmission of patients previously admitted to hospital for AECOPD; however, factors related to readmission in patients who are triaged in emergency departments (EDs) and sent directly home are poorly understood. We postulate that patients seen in the ED for AECOPD and directly sent home have a high readmission rate, and we suspect that inadequate management and follow-up contribute to this high readmission rate. We conducted a 1-year retrospective study of all patients seen in the ED for AECOPD at an inner-city tertiary care hospital; 30- and 90-day readmission rates for COPD and all-cause admissions to the ED and hospital were determined. Patients discharged directly home from the ED were compared with those admitted to hospital for management. Patient, treatment, and system variables that could potentially impact readmission were documented. Multivariate Poisson regression models were used to determine which factors predicted readmissions. The readmission rates in the ED group (n=240) were significantly higher than that in the hospitalized group (n=271): 1) the 90-day ED readmissions (1.29 vs 0.51, p<0.0001) and 30-day ED readmissions (0.54 vs 0.20, p<0.0001) (ED vs hospitalized groups) were significantly higher in the ED group; 2) the time to first readmission was significantly shorter in the ED group than in the hospitalized group (24.1±22 vs 31.8±27.8 days; p<0.05). Cardiovascular comorbidities (p<0.00001), substance abuse disorder (p<0.001), and mental illness (p<0.001) were the strongest predictors of readmission in the ED group. Age (p<0.01), forced expiratory volume in 1 second (p<0.001), and cardiovascular comorbidities (p<0.05) were the best predictors for both 30- and 90-day COPD readmission rates in the ED group. Only 50% of the ED group patients received bronchodilators, oral steroids, and antibiotics inclusively, and only 68% were referred for community follow-up. The need for oral steroids to treat AECOPD predicted future 90-day COPD readmissions in the ED group (p<0.003). Patients discharged directly home from EDs have a significantly higher risk of readmission to EDs than those who are hospitalized. One possible reason for this is that COPD management is variable in EDs with <50% receiving appropriate therapy.