The emerging literature regarding the novel coronavirus disease 2019 (COVID-19) suggests that patients with olfactory dysfunction (OD) have a milder disease course with improved clinical symptomatology and outcomes. This study utilized the National Library of Medicine’s PubMed/MEDLINE database to query for articles describing major outcomes in patients with COVID-19 with or without OD. Of the 1284 examined studies, 26 were included for a total of 11,408 patients (35.9% with OD). When compared with patients with OD, patients without OD were 5.3 times more likely to experience hospitalization (odds ratio, 5.28 [95% CI, 4.64-6.01]; P < .001), 7.0 times more likely to undergo intubation or ventilation (7.01 [5.52-8.90], P < .001), and 7.0 times more likely to die (6.97 [3.54-13.74], P < .001). This association between OD and COVID-19 outcomes may play an important role in patient risk stratification and counseling and early identification of potentially severe cases, and it may encourage future investigations regarding the infectivity and immune response to SARS-CoV-2.
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