Background: Chronic obstructive pulmonary disease (COPD) is a heterogeneous systemic syndrome that often coexists with multiple comorbidities. In highly complex COPD patients, the role of the Cumulative Illness Rating Scale (CIRS) as a risk predictor of COPD exacerbation is not known.
Objective: The objective of this study was determine the effectiveness of the CIRS score in detecting the association of comorbidities and disease severity with the risk of acute exacerbations in COPD patients.
Methods: In total, 105 adults with COPD (mean age 72.1 ± 9.0 years) were included in this prospective study. All participants at baseline had at least two moderate exacerbations or one leading to hospitalization. The primary outcome was a composite of moderate or severe COPD exacerbation during the 12 months of follow-up.
Results: The CIRS indices (CIRS total score, Severity Index and Comorbidity Index) showed a positive correlation with modified Medical Research Council (mMRC), COPD assessment test (CAT) and a negative correlation with forced expiratory volume in the first second (FEV1), Forced Vital Capacity (FVC), and FEV1/FVC. The three CIRS indices were able to predict the 12-month rate of moderate or severe exacerbation (CIRS Total Score: Hazard Ratio (HR) = 1.12 (95% CI: 1.08-1.21); CIRS Severity Index: HR = 1.21 (95% CI: 1.12-1.31); CIRS Comorbidity Index = 1.58 (95% CI: 1.33-1.89)).
Conclusions: Among patients with COPD, the comorbidity number and severity, as assessed by the CIRS score, influence the risk in moderate-to-severe exacerbations. The CIRS score also correlates with the severity of respiratory symptoms and lung function.
Keywords: Cumulative Illness Rating Scale; acute exacerbation of COPD (AECOPD); chronic obstructive pulmonary disease (COPD); comorbidity; multimorbidity.