Mortality in patients with COPD exacerbations attending emergency departments (BMC Medicine)

Background: Limited information is available about predictors of short-term outcomes in patients with exacerbations of chronic obstructive pulmonary disease (eCOPD) attending an emergency department (ED). Such information could help stratify these patients and guide medical decision making. The aim of this study was to develop a clinical prediction rule for short-term mortality during hospital admission or within a week after the index ED visit. Methods: Prospective cohort study of eCOPD patients attending the EDs of 16 participating hospitals. Recruitment started in June 2008 and ended in September 2010. Information on possible predictor variables was recorded during the time the patient was evaluated in the ED, at the time a decision was made to admit the patient to the hospital or discharge home, and during follow-up. Main short-term outcomes were death during hospital admission or within one week of discharge to home from the ED, as well as at death within one month of the index ED visit. Multivariate logistic regression models were developed in a derivation sample and validated in a validation sample. The score was compared with other published prediction rules for COPD stable patients. Results: 2,487 patients were included in the study. Predictors of death during hospital admission, or within one week of discharge to home from the ED were patient age, baseline dyspnea, previous need for long-term home oxygen therapy or noninvasive mechanical ventilation, altered mental status, and use of inspiratory accessory muscles or paradoxical breathing upon ED arrival (AUC: 0.85). Addition of arterial blood gas parameters (PO2, pH and PCO2) did not improve the model. The same variables were predictors of death at one month (AUC: 0.85). Compared with other commonly used tools for predicting the severity of COPD in stable patients, our rule was significant better. Conclusions: Five clinical predictors easily available in the ED-and also in the primary care setting-can be used to create a simple and easy-to-obtain score that allows clinicians to stratify patients with eCOPD upon ED arrival and guide the medical decision making process.