Background It is essential to avoid admission of patients with undetected corona virus disease 2019 (COVID-19) to hospitals’ general wards. Even repeated negative reverse transcription polymerase chain reaction (RT-PCR) results do not rule-out COVID-19 with certainty. The study aimed to evaluate a rule-out strategy for COVID-19 using chest computed tomography (CT) in adults being admitted to the emergency department and suspected of COVID-19. Methods In this prospective, single centre, diagnostic accuracy cohort study, consecutive adults (≥ 18 years) presenting with symptoms consistent with COVID-19 or previous contact to infected individuals, admitted to the emergency department and supposed to be referred to general ward were included in March and April 2020. All participants underwent low-dose chest CT. RT-PCR- and specific antibody tests were used as reference standard. Main outcome measures were sensitivity and specificity of chest CT. Predictive values were calculated based on the theorem of Bayes using Fagan’s nomogram. Results Of 165 participants (56.4% male, 71 ± 16 years) included in the study, the diagnosis of COVID-19 was confirmed with RT-PCR and AB tests in 13 participants (prevalence 7.9%). Sensitivity and specificity of chest CT were 84.6% (95% confidence interval [CI], 54.6–98.1) and 94.7% (95% CI, 89.9–97.7), respectively. Positive and negative likelihood ratio of chest CT were 16.1 (95% CI, 7.9–32.8) and 0.16 (95% CI, 0.05–0.58) and positive and negative predictive value were 57.9% (95% CI, 40.3–73.7) and 98.6% (95% CI, 95.3–99.6), respectively. Conclusion At a low prevalence of COVID-19, chest CT could be used as a complement to repeated RT-PCR testing for early COVID-19 exclusion in adults with suspected infection before referral to hospital’s general wards. Trial registration ClinicalTrials.gov: NCT04357938 April 22, 2020.
【저자키워드】 COVID-19, severe acute respiratory syndrome coronavirus 2, Prevalence, Computed tomography, Reverse transcriptase polymerase chain reaction, Sensitivity and specificity, 【초록키워드】 Infection, diagnostic, nomogram, complement, Symptom, RT-PCR, cohort study, emergency department, Predictive value, Computed tomography, Chest computed tomography, reverse transcription polymerase chain reaction, polymerase chain reaction, specificity, Diagnostic accuracy, Chest CT, Accuracy, antibody tests, low-dose, male, Patient, Referral, predictive values, reverse transcription, Antibody test, Admission, reference standard, Contact, Negative predictive value, Virus Disease, referred to, Trial registration, 95% CI, RT-PCR testing, 95% confidence interval, All participants, infected individuals, certainty, outcome measure, participant, exclusion, likelihood ratio, positive, theorem, repeated, polymerase chain, Result, evaluate, calculated, were used, presenting, All participant, diagnosis of COVID-19, prevalence of COVID-19, with COVID-19, 【제목키워드】 Admission,