Predictors of Mortality After Hospitalization for COPD Exacerbation

In patients hospitalized for a severe exacerbation of chronic obstructive pulmonary disease (COPD), predictors of 1-year mortality after index hospitalization included patient age, prior hospitalization for COPD exacerbation, aspects of the COPD index event, and features of the hospital in which the patient was treated, according to the results of a recent prospective, observational, multicenter Spanish cohort study published in BMC Pulmonary Medicine.

Two cohorts were included in the analysis: a derivation cohort (n=1420) and a validation cohort (n=3949). In the derivation cohort, the mean patient age was 73.4 years, 89.8% of the participants were men, 44.0% had a Charlson Comorbidity Index (CCI) ≥3, and 76.7% had been previously hospitalized for COPD. In that cohort, the in-hospital mortality rate was 5%.

In contrast, in the validation cohort, the mean patient age was 72.7 years, 85.5% of the participants were men, 27.4% had a CCI ≥3, and 51.3% had been previously hospitalized for COPD. The in-hospital mortality rate in the validation cohort was 4.3%. Significant differences were reported between the 2 cohorts in the rates of ischemic heart disease, cerebrovascular disease, and peripheral vascular disease.

On the basis of univariate analysis performed in the derivation sample, significant differences were observed between patients who had died within 1 year of the index hospitalization vs those who had not with respect to age, smoking habits, CCI, presence of comorbidities (including ischemic heart disease, cardiac failure, peripheral vascular disease, cerebrovascular disease, and dementia), prior hospital admission for a COPD exacerbation, mean number of hospitalizations for COPD exacerbations in the prior year, level of airway severity obstruction (percentage of forced expiratory volume in 1 second [FEV1%] and Global Initiative for Chronic Obstructive Lung Disease stages of obstruction), and mean partial pressure of carbon dioxide in arterial blood (PACO₂) level on arrival in the emergency department.

Per the multivariate analysis conducted in the validation sample, independent variables that were significantly linked to 1-year mortality rates included age (P <.0001), comorbidities (ie, prior presence of cardiac, peripheral vascular, or cerebrovascular disease or dementia; P <.0001), hospital admission for a COPD exacerbation in the prior year (P <.0001), and PACO₂ level >55 mm Hg at arrival in the emergency department (P =.0917 [patients 45 to 55 years vs <45 years of age] and P =.001 [patients >55 years of age vs <45 years of age]).

In this cohort, the hospital features associated with 1-year mortality rates included the size of the hospital (P <.0001) and whether the hospital had a respiratory ward (P =.04).

The investigators concluded that the identification of factors associated with 1-year mortality after hospitalization for a COPD exacerbation might help provide tools for more targeted evaluation of such patients and interventions that might prevent premature death in this population.

Reference

Esteban C, Castro-Acosta A, Alvarez-Martínez CJ, Capelastegui A, López-Campos JL, Pozo-Rodriguez F. Predictors of one-year mortality after hospitalization for an exacerbation of COPD. BMC Pulm Med. 2018;18(1):18.