Comparison of the prognostic capability of two comorbidity indices in patients with chronic obstructive pulmonary disease, in real-life clinical practice

Abstract

Background: Comorbidities are a major cause of death in chronic obstructive pulmonary disease (COPD). The COPD-comorbidity test (COTE) index was designed to measure comorbidity burden in this disease. The objective of this study was to compare the capability of COTE and the non-COPD specific Charlson comorbidity index (CCI) to predict all-cause mortality in real-life conditions.

Methods: Retrospective observational study, carried out in two different series of consecutive COPD patients including, respectively, 790 and 439 subjects. The COTE and non-age-adjusted CCI indices were calculated and the values of the C-statistic for predicting all-cause mortality were compared for both indices.

Results: Median follow-up was 54 months and there were 321 deaths within this period of time. The value of the C-statistic for the CCI was significantly higher than for the COTE index in both groups.

Conclusion: When used in real-life clinical practice, the value of the CCI to predict all-cause mortality in COPD seems higher than that of the COTE index.

Keywords: COTE index; Charlson comorbidity index; chronic obstructive pulmonary disease; comorbidity; mortality; prognosis.