Cardiovascular components of the COTE index predict acute exacerbations and healthcare costs in patients with chronic obstructive pulmonary disease: a nationwide linked cohort study.

BACKGROUND

The COPD-specific CO-morbidity Test (COTE) index is an established predictor of mortality in patients with chronic obstructive pulmonary disease (COPD), but its prognostic value for acute exacerbations and healthcare costs remains unclear. In particular, the impact of cardiovascular diseases on these clinical outcomes is poorly understood in Asian patients with COPD. Therefore, we aimed to assess the associations between baseline cardiovascular diseases within the COTE index and acute exacerbations and healthcare costs over a 1-year follow-up.

METHODS

We analyzed data from 2,474 patients with stable COPD from the Korean COPD Subgroup Study linked to the national Health Insurance Review and Assessment Service claims. Associations between baseline cardiovascular components within the COTE index and clinical outcomes were assessed using zero-inflated negative binomial and gamma regression models. To further evaluate the independent effect of cardiovascular components, stratified analyses by COTE risk group were performed.

RESULTS

Comorbidities were highly prevalent (95.4%), with cardiovascular diseases being the most common. Among cardiovascular disease, myocardial infarction (MI) and ischemic stroke were significant predictors of severe exacerbations during the 1-year follow-up. Higher COTE index was significantly associated with increased healthcare costs. Notably, ischemic stroke, coronary artery disease (CAD) and congestive heart failure showed the strongest association with higher healthcare costs. In stratified analyses, MI and ischemic stroke predicted severe exacerbations only in the high-risk COTE group, whereas CAD and ischemic stroke were linked to increased healthcare costs across all COTE groups.

CONCLUSIONS

Baseline cardiovascular comorbidities within the COTE index are independently associated with severe exacerbations and increased healthcare costs in patients with COPD over a 1-year follow-up. Collectively, these results support the clinical utility of the COTE index, especially cardiovascular diseases, in identifying high-risk patients for exacerbations and healthcare costs in COPD.