BACKGROUND: Patients with COPD typically have multiple underlying comorbidities. The relationship between existing comorbidities and hospitalizations among patients with COPD warrants further examination.
OBJECTIVE: Evaluate the association between comorbidities and number of hospitalizations among patients with COPD.
METHODS: A cohort of patients with evidence of COPD diagnosis was identified using Humana’s claims database. Patients aged 40-89 years who were continuously enrolled for 12 months prior to and 24 months after the first COPD diagnosis (index date) during January 1, 2008-December 31, 2010 were identified. Comorbidities were assessed during 12 months prior and 12 months after the index date, using the Agency for Health Research and Quality Clinical Classification Software methodology. Based on prevalence and clinical expert consultation, 11 comorbidities were selected: coronary artery disease (CAD), congestive heart failure (CHF), cerebrovascular disease (CVD), chronic kidney disease (CKD), type 2 diabetes mellitus (T2DM), anxiety, depression, obesity, osteoarthritis, osteoporosis and sleep apnea. All-cause and COPD-related hospitalizations were assessed in the 24-month period after the index date. Generalized linear models with log link and negative binomial variance functions were used to determine the association between presence of comorbidities and hospitalizations, controlling for baseline patient characteristics.
RESULTS: A total of 52,643 patients with evidence of COPD diagnosis were identified with 92% having at least 1 comorbidity of interest; 48% had CAD, 44% osteoarthritis, 41% T2DM, 28% CHF, 27% CVD, 27% depression, 26% CKD, 23% anxiety, 20% osteoporosis, 20% obesity and 17% sleep apnea. Having a comorbidity of interest was associated with a higher number of all-cause hospitalizations compared to not having that comorbidity; CHF, CAD, and CVD had the strongest associations with all-cause hospitalizations (mean ratio 1.56, 1.32, and 1.30 respectively; all P≤0.001). Having a comorbidity (except osteoarthritis, CKD, and obesity) was also associated with a higher number of COPD-related hospitalizations; CHF, anxiety, and sleep apnea had the strongest associations (mean ratio 2.01, 1.32, and 1.21, respectively; all P≤0.001).
CONCLUSIONS: Comorbidities are common in patients with COPD and are associated with higher all-cause and COPD-related hospitalizations. Assessment of comorbidities in patients with COPD, especially CHF, CAD, CVD, anxiety and sleep apnea may help identify subgroups of patients at increased risk of hospitalization.
