Sleep Apnea and COVID-19 Mortality and Hospitalization

A report describing 5,700 patients with coronavirus disease (COVID-19) identified that common risk factors for poor outcomes are older age, minority ethnicity, obesity, hypertension, and diabetes (1). However, mortality and hospitalizations, estimated by the CDC COVID-19 Response Team to occur in 1.8–3.4% and 20.7–31.4% of COVID-19–positive individuals, respectively (2), are not fully explained by recognized risk factors. Sleep apnea—prevalent in older, obese, and minority individuals—increases risk for COVID-19 comorbidities and may contribute to poor outcomes by exacerbating or causing endothelial dysfunction, inflammation, oxidative stress, microaspiration, and lung injury (3–8). Although prior reports of COVID-19 risk factors have not identified sleep apnea as a prevalent risk factor, data were from healthcare systems where clinical recognition of sleep apnea is markedly underrecognized. Given its association with recognized COVID-19 comorbidities and physiological plausibility, we analyzed electronic health record (EHR) data (9) from a large New England healthcare system to ask whether sleep apnea is an unrecognized risk factor for COVID-19–related death, hospitalization, ventilator use, and ICU admission among patients with positive COVID-19 diagnostic testing. Methods The sample was adult nonemployee participants with positive COVID-19 RNA PCR diagnostic results who had available demographic data, a minimum of two clinical notes, two encounters, and three International Classification of Disease (ICD) diagnoses of any disease (to minimize the effect of minimal EHR documentation in participants with out-of-network care). Participants were further restricted to include those with either zero or two or more ICD-9 or ICD-10 diagnoses of sleep apnea or obstructive sleep apnea on different dates (to minimize the effect of rule-out diagnosis codes). Natural language processing (10) was used to obtain documentation of continuous positive airway pressure (CPAP) usage in the year before the first COVID-19 test.