Reliability of comorbidity indices as predictive indicators for frequent severe chronic obstructive pulmonary disease exacerbations.

Introduction: The relationship between comorbidities and chronic obstructive pulmonary disease (COPD) is two-sided. As the number of comorbidities increases, frequency of acute exacerbations of COPD (AECOPD) consequently increases. Comorbidity indices can be used to evaluate comorbidities while managing COPD patients. We aimed to compare comorbidity indices such as the Charlson comorbidity index (CCI), comorbidities in COPD index (COMCOLD) and COPD specific comorbidity test (COTE) regarding exacerbation frequency.

Materials and methods: Participants hospitalized for AECOPD were included in this bidirectional case-control study. Exacerbation severity, frequency, further exacerbations over a one-year follow-up period and CCI, COMCOLD, and COTE scores were recorded. High and low comorbidity groups were compared regarding AECOPD frequency, severity, and further exacerbations.

Result: Ninety-two patients were enrolled. The frequency of AECOPD was significantly higher in high-comorbidity groups (p= 0.026 for CCI; 0.015 for COTE; 0.012 for COMCOLD) than that in low-comorbidity groups. Severe AECOPD was significantly higher in all high-comorbidity groups according to the indices. Median number of exacerbations during the one-year follow-up period was significantly higher in the high-comorbidity groups defined by CCI [0 (0-4) vs. 1 (0-4), p<0.001 and COMCOLD 0 (0-4) vs. 1 (0-3), p= 0.007].

Conclusions: Comorbidities are among the most important risk factors for AECOPD. Managing comorbidities begins with their identification, followed by appropriate interventions. Therefore, using at least one comorbidity index during assessment ensures that comorbidities are not overlooked during diagnostic and therapeutic processes. CCI, COTE, and COMCOLD comorbidity indices can be used in predicting COPD exacerbations.