Relationship Between Severity Classification of Acute Exacerbation of Chronic Obstructive Pulmonary Disease and Clinical Outcomes in Hospitalized Patients

Abstract

BACKGROUND Limited data are available regarding the impact of the potential validation of the Canadian Thoracic Society (CTS) guidelines recommendations in classifying patients with an acute exacerbation of chronic obstructive pulmonary disease (AECOPD) in simple and complex. The aim of the present study was to assess the CTS recommendations regarding risk stratification on clinical outcomes among patients hospitalized with an AECOPD. METHODS We developed a retrospective cohort study of patients admitted to one tertiary hospital with a diagnosis of AECOPD. The main clinical outcome was the percentage of treatment failure. Secondary outcomes were 30-day, 90-day, and 1-year readmission and mortality rate, length of stay in hospital, intensive care unit (ICU) admission rate, time to readmission, and time to death. Multivariate analyses were performed using 1-year mortality rate as the dependent measures. RESULTS One hundred forty-three patients composed the final study population, most of them (106 [74.1%)] classified as complex acute exacerbation (C-AE) of COPD. C-AE patients had similar rate of treatment failure compared with simple acute exacerbation (S-AE) of COPD (31.1% vs. 27%; p = 0.63). There were no differences regarding the length of stay in hospital, ICU admission rate, and 30-day, 90-day, and 1-year readmission rate. C-AE patients had faster declined measures on time to death (691.6 ± 430 days vs. 998.1 ± 355 days; p = 0.02). In the multivariate analysis, after adjusting for comorbidity, lung function and previous treatment, C-AE patients had a significant higher mortality at one year (Odds Ratio [OR] = 4.9 (Confidence Interval [CI] 95%: 1.16-21); p = 0.031). CONCLUSIONS In hospitalized patients with an AECOPD, CTS classification, according to the presence of risk factors, was not associated with worse short-term clinical outcomes although it is related with long-term mortality.