The Impact of Chest Computed Tomography in a COVID-19 Reference Hospital - First Wave - Distrito Federal - Brazil

Objectives: To evaluate the diagnostic accuracy of chest CT for the diagnosis of COVID-19 associated with the clinical presentation and in relation to the PCR-RT. Sensitivity, specificity, positive predictive value and negative predictive value, gender, age group and degree of lung involvement will be evaluated. Methods: We evaluated 1545 patients suspected of COVID-19 with chest CT, delineating the age range and degree of lung involvement, and 306 patients suspected of COVID-19 with chest CT and PCR-RT, delineating sensitivity, specificity, accuracy, prevalence, positive predictive value, and negative predictive value. Results: Of the 1545 examinations, 53% were men and 47% were women, there was greater involvement in the 50-59 age group. In the pulmonary study, 32.45% were normal, 12.50% were other diseases and 55.05% were COVID-19. In the degree of lung involvement 37.70% were mild (up to 25% of the lung area), 35.76% were moderate (25 to 50% of the lung area), and 26.54% were severe (between 50 and 100%). In the distribution by age group of patients affected by covid-19, there was a greater involvement between 50-59 years with 56% of patients classified between moderate (27.6%) and severe (28.0%). Between tomography and PCR-RT, the sensitivity was 68.8%, specificity 59.5%, accuracy 91.3%, with prevalence 31.9%, positive predictive value 44.3% and negative predictive value 80.3%, in females, sensitivity 55.3%, positive predictive value 37.1%, negative predictive value 75.3%, in males, sensitivity 81.6%, positive predictive value 50, 6 and negative predictive value 86.6%.The sensitivities are different between the genders with p of 0.005 and specificity of 0.938, and with age effect, starting at 45 years we have a p of 0.057 that decreases to 0.006 at 80 years for sensitivity and specificity. Conclusions: The sensitivity and accuracy of CT scan in relation to PCR-RT was significant, highlighting that PCR-RT is difficult to perform and that may have affected the results obtained, reducing the sensitivity by false negative PCR-RT. Sensitivity increases with prevalence and is more significant in the older age group and in men, who are more affected in this pathology.Funding Information: None. Declaration of Interests: None.Ethics Approval Statement: The present study was approved by the Research Ethics Committee of the Fundação de Ensino e Pesquisa FEPECS/Escola Superior de Ciências da Saúde ESCS. All participants were exempted from signing the informed consent form.