Background: The objective evaluation of the olfactory function of coronavirus disease 2019 patients is difficult because of logistical and operator-safety problems. For this reason, in the literature, the data obtained from psychophysical tests are few and based on small case series. Methods: A multicenter, cohort study conducted in seven European hospitals between March 22 and August 20, 2020. The Sniffin-Sticks test and the Connecticut Chemosensory Clinical Research Center orthonasal olfaction test were used to objectively evaluate the olfactory function. Results: This study included 774 patients, of these 481 (62.1%) presented olfactory dysfunction (OD): 280 were hyposmic and 201 were anosmic. There was a significant difference between self-reported anosmia/hyposmia and psychophysical test results ( p = 0.006). Patients with gastroesophageal disorders reported a significantly higher probability of presenting hyposmia (OR 1.86; p = 0.015) and anosmia (OR 2.425; p < 0.001). Fever, chest pain, and phlegm significantly increased the likelihood of having hyposmia but not anosmia or an olfactory disturbance. In contrast, patients with dyspnea, dysphonia, and severe-to-critical COVID-19 were significantly more likely to have no anosmia, while these symptoms had no effect on the risk of developing hyposmia or an OD. Conclusions: Psychophysical assessment represents a significantly more accurate assessment tool for olfactory function than patient self-reported clinical outcomes. Olfactory disturbances appear to be largely independent from the epidemiological and clinical characteristics of the patients. The non-association with rhinitis symptoms and the high prevalence as a presenting symptom make olfactory disturbances an important symptom in the differential diagnosis between COVID-19 and common flu.
【저자키워드】 COVID-19, SARS-CoV-2, olfactory dysfunction, Anosmia, Smell, Hyposmia, Olfaction, parosmia, 【초록키워드】 coronavirus disease, Clinical characteristics, hospital, risk, Symptom, clinical outcomes, Clinical research, cohort study, Prevalence, Probability, Case series, Dyspnea, Patient, Connecticut, epidemiological, multicenter, flu, patients, differential diagnosis, chest pain, olfactory, olfactory function, significant difference, problems, center, disorder, European, likelihood, independent, Seven, significantly increased, evaluate, significantly more, reported, conducted, were used, significantly higher, had no, presenting, these symptom, 【제목키워드】 multicenter study, European,