In a review of US-based hospital admission data from May 2017 to July 2018, a team of investigators found worsened readmission and mortality rates among hospitalized COPD patients who screened positive for sleep apnea as well.
The findings add evidence to the burden of belated sleep apnea diagnoses and care in the US population, and the effect more severe cases may have on hospital resources and personnel.
Investigators, led by Mario Naranjo, MD, of the Albert Einstein Medical Center in Philadelphia, sought to assess the presence of unrecognized and untreated obstructive sleep apnea cases among patients with COPD who present to the hospital with exacerbations. As they noted, COPD is already the second most common cause of hospital admission in the US.
The team hypothesized sleep apnea—among the most common respiratory conditions in the country—is increasing readmission rates of such patients.
Their review of COPD exacerbation-admitted patients to a hospital in the span of 14 months included those who were also screened for previously unrecognized and untreated obstructive sleep apnea. Such patients were provided a sleep questionnaire before undergoing high-resolution pulse-oximetry (HRPO) or portable sleep monitoring (PM) studies.
Naranjo and colleagues compared the rates of COPD patients readmitted to the hospital within 30, 90, and 180 days of their initial admission, as well as overall mortality rates, among those who did and did not test positive for obstructive sleep apnea.
Of the 380 patients hospitalized for COPD exacerbations, 256 were screened for sleep apnea with a questionnaire. Almost all (n = 238) underwent overnight HRO/PM follow-up. Fewer than half (n = 111; 46.6%) were reported to have obstructive sleep apnea; 28.6% had a mild form, 9.7% moderate, and 8.4% severe
Patients with obstructive sleep apnea reported greater mean body mass index (33.9 kg/m2) than those without (30.3 kg/m2) and a nearly three-fold greater prevalence of heart failure (19.8% vs 7.1%). Other baseline characteristics and demographics between the 2 COPD patient groups were similar, though.
Increasingly severe cases of obstructive sleep apnea in COPD patients were associated with greater 30-day readmission rates than those with just COPD: 2.05 times greater in patients with a mild form (32.4% vs 18.9%); 6.68 times greater in patients with a moderate form (60.9%); and 10.1 times greater in patients with a severe form (70%).
Investigators also observed greater readmission rates among COPD patients with obstructive sleep apnea at 90 and 180 days, a greater all-cause mortality in patients with both conditions than those with just COPD (P< .01), and a shorter time to hospital readmission or death in COPD patients with greater sleep apnea severity (P< .01).
Obstructive sleep apnea has been long touted by clinicians and specialists as among the most prevalent and burdensome comorbid conditions in their patients—despite the specialty—yet lacks consistent screening and preventive care measures.
In an interview with HCPLive® last year, Neomi Shah, MD, MPH, associate division chief of Pulmonary Critical Care & Sleep Medicine at Mount Sinai, said her field is still in the “infancy stages” of interpreting the reach and burden of sleep apnea on cardiovascular and pulmonary conditions—some of which are the most prevalent drivers of patient hospitalization today.
“I think appropriately screening, appropriately referring, and diagnosing sleep disorders is very important, because it does have an effect on a lot of health outcomes including obesity, including your dietary intake, which can drive numerous other outcomes and health endpoints,” Shah said.
Naranjo and colleagues concluded its effect as an unnoticed, untreated comorbidity in patients with COPD is distinct, affecting both hospital readmission and mortality risk.
“Obstructive sleep apnea is a highly prevalent and underdiagnosed condition which may impact the outcome of COPD,” they wrote.