COPD Outcomes: Impact of Undiagnosed OSA
—A recent study examined whether having unrecognized and untreated OSA increased chances of hospital readmissions for patients admitted for COPD exacerbation.
Chronic obstructive pulmonary disease (COPD) is a progressive lung condition characterized by airway inflammation that destroys tissue and eventually causes respiratory failure.1 COPD is one of the most common causes of death in the United States.1 Hospitalizations for COPD are quite common, and, according to the authors of a new study, readmission to the hospital for any reason among patients with COPD is estimated to be >20%.2,3 However, most of these readmissions are not directly caused by COPD exacerbations, but instead are the result of progressive comorbidities, such as congestive heart failure (CHF), arrhythmia, or uncontrolled diabetes.
A new study by Naranjo and colleagues examined the effect of undiagnosed obstructive sleep apnea (OSA) on hospital readmissions within 30 days for patients discharged after treatment of a COPD exacerbation from an inner-city hospital.1 According to the coauthors, previous studies have not specifically analyzed this relationship, and they say that at least 1 study has shown that the prevalence of co-morbid OSA in moderate to severe COPD was reported to be as high as 66%.4
An earlier study by the same group of investigators showed an improvement in survival with a novel 2-step screening method of administrating a sleep questionnaire called STOP (snoring, tiredness during daytime, observed apnea, and high blood pressure), followed by in-house high-resolution pulse oximetry (HRPO).5 The current study’s primary aim was to evaluate the impact of OSA on inner-city hospital readmission within 30 days and subsequent mortality for patients previously discharged after treatment for a COPD exacerbation.
The authors reviewed patients admitted for COPD exacerbation between May 2017 and July 2018. Those who had been screened for previously undiagnosed and unmanaged OSA with a sleep questionnaire and who subsequently underwent HRPO or portable sleep monitoring (PM) study (N=238) were included in the study. In addition to the primary endpoint, the investigators also looked at the impact on 90- and 180-day readmissions and all-cause mortality across all OSA categories.1
Nearly half of patients in this study (111/238; 46.6%) were found to have OSA. Of the total patient population, 28.6%, 9.7%, and 8.4% had mild, moderate, and severe OSA, respectively. Among COPD patients with mild, moderate, and severe OSA, odds of 30-day readmission were 2.05 times (32.4% vs 18.9%; 95% CI: 1.05, 4.03), 6.68 times (60.9% vs 18.9%; 95% CI: 2.59, 17.23), and 10.01 times (70 % vs 18.9%; 95% CI: 3.49, 28.75) higher than for patients without OSA, respectively. When combining all OSA severity categories, the odds of 30-day readmission were 3.5 times higher (95% CI: 1.97, 6.29) than for patients without OSA (45.1% vs 18.9%, P<0.01).1
For patients with OSA, 90- and 180-day readmission rates were also greater, and all-cause mortality was higher (P<0.01). For those with more severe OSA, the time to hospital readmission or death was shorter (P<0.01). Most baseline characteristics of those with or without OSA were similar, but those with OSA had a higher BMI (33.9 vs 30.3 kg/m2), a higher prevalence of heart failure (19.8% vs 7.1%), and were predominantly male (60.4% vs 49.6%).1
“Patients hospitalized with COPD who also have undiagnosed sleep disordered breathing are at higher risk of getting readmitted within 30 days,” says the study’s senior author, Suni Sharma, MD, Division of Pulmonary, Critical Care and Sleep Medicine, West Virginia University, Morgantown, WV. “The risk of readmission increases with the severity of underlying sleep apnea and extends to up to 6 months. Furthermore, patient with COPD and undiagnosed sleep disordered breathing had worse survival than COPD alone at 6 months.”
Sharma says that next steps for research have been clearly defined by this study and others. “Sleep disordered breathing is a highly under-recognized and under-treated condition,” he says. “Recent data suggest that screening high-risk hospitalized patients for sleep disordered breathing and early intervention may improve outcome. The next logical step would be to study whether early treatment of sleep apnea will positively impact outcome of hospitalized COPD patients….Larger , multi-centric study is required to confirm these findings.”
Published:
References
- 1. Naranjo M, Willes L, Prillaman BA, Quan SF, Sharma S. Undiagnosed Obstructive Sleep Apnea May Significantly Impact Outcomes in Adults Admitted for COPD in an Inner-City Hospital. Chest. 2020 Apr 2. pii: S0012-3692(20)30568-7. doi:10.1016/j.chest.2020.03.036 [Epub ahead of print]
- 2. Elixhauser A, Au D, Podulka J. Readmissions for Chronic Obstructive Pulmonary Disease, 2008: Statistical Brief #121. Healthcare Cost and Utilization Project (HCUP) Statistical Briefs [Internet]. Rockville (MD): Agency for Healthcare Research and Quality (US); 2006-2011 Sep.
- 3. Donovan L, Feemster L, Udris E et al. Poor Outcomes Among Patients With Chronic Obstructive Pulmonary Disease With Higher Risk for Undiagnosed Obstructive Sleep Apnea in the LOTT Cohort. J Clin Sleep Med. 2019;15(1):71-77.
- 4. Soler X, Gaio E, Powell F et al. High Prevalence of Obstructive Sleep Apnea in Patients with Moderate to Severe Chronic Obstructive Pulmonary Disease. Ann Am Thorac Soc. 2015;12(8):1219-25.
- 5. Konikara J, Tavella R, Willes, L, Kavuru M, Sharma S. Early Recognition of Obstructive Sleep Apnea in Patients Hospitalized with COPD Exacerbation is Associated with Reduced Readmission. Hosp Pract (1995). 2016;44:41-47. doi: 10.1080/21548331.2016.1134268