The Economic Burden of Comorbid Obstructive Sleep Apnea Among Patients with Chronic Obstructive Pulmonary Disease

BACKGROUND: Chronic obstructive pulmonary disease (COPD) imposes a substantial burden on patients and the health care system. The presence of comorbid obstructive sleep apnea (OSA) has been shown to increase the risk of morbidity and mortality in patients with COPD. There is limited information available on the incremental economic burden of comorbid OSA among patients with COPD. OBJECTIVE: To estimate the incremental health care resource utilization (HCRU) and direct medical costs associated with having comorbid OSA among individuals with COPD in a nationally representative commercially insured population in the United States. METHODS: We identified individuals with a diagnosis of COPD between January 2008 and December 2014, with and without OSA, from the IQVIA PharMetrics Plus database. The index date was defined as the first claim with a diagnosis of COPD. All baseline characteristics were measured in the 12-month pre-index period, and all outcomes were measured in the 12-month post-index period. The odds of experiencing one or more hospitalizations and emergency room (ER) visits were compared between individuals with and without comorbid OSA using logistic regression models. Twelve-month total, physician office visit, and other outpatient costs were compared between individuals with and without OSA using generalized linear models. To account for a high proportion of zero costs, 2-part models were fit to examine inpatient, ER visit, and pharmacy costs. Average marginal costs were estimated to compare the costs of individuals with and without OSA. All costs represented direct medical costs from the health plan perspective. RESULTS: Following application of inclusion and exclusion criteria, the study sample included 85,940 individuals with COPD alone and 7,942 individuals with COPD and OSA. The odds of experiencing a hospitalization and an ER visit were significantly higher in the COPD-OSA cohort than in the COPD-only cohort (hospitalization OR = 1.45, 95% CI = 13531.38-1.53; ER visit OR = 1.24, 95% CI = 1.18-1.30). The average difference in total cost between individuals with and without comorbid OSA was $8,144 (95% CI = $7,295-$8,993). The average difference in costs for physician office visits and other outpatient services was $392 (95% CI = $351-$433) and $2,831 (95% CI = $2,463-$3,200), respectively. Among individuals with a non-zero, strictly positive inpatient cost, the average difference in inpatient costs was $2,792 (95% CI = $1,354-$4,230). Similarly, among individuals with strictly positive pharmacy and ER costs, the average difference in costs between individuals with and without comorbid OSA was $1,772 (95% CI = $1,590-$1,953) and $144 (95% CI = $101-$188), respectively. CONCLUSIONS: Total medical cost and costs for inpatient, ER, pharmacy, physician office visit, and other outpatient services were higher among COPD patients with comorbid OSA compared to patients without. The economic burden of comorbid OSA among patients with COPD in the commercially insured U.S. population is substantial.