False-negative real-time polymerase chain reaction tests in COVID-19 patients: an epidemiological analysis of 302 patients

Objectives: Patients who arrive at the emergency department (ED) with COVID-19, who test negative at the first real-time polymerase chain reaction (RT-PCR), represent a clinical challenge. This study aimed to evaluate if the clinical manifestation at presentation, the laboratory and imaging results, and the prog-nosis of COVID-19 differ in patients who tested negative at the first RT-PCR compared with those who tested positive and also to evaluate if comorbid conditions patient-related or the period of arrival are associated with negative testing. Study design: We retrospectively collected clinical data of patients who accessed the ED from March 1 to May 15, 2020. Methods: We compared clinical variables, comorbid conditions, and clinical outcomes in the two groups by univariate analysis and logistic regression. Results: Patients who tested negative at the first RT-PCR showed a higher prevalence of cardiopathy, immunosuppression, and diabetes, as well as a higher leukocyte and lower lymphocyte counts compared with patients who tested positive. A bilateral interstitial syndrome and a typical pattern at computed tomography scan were prevalent in the test-negative group. Test-negative patients were more likely to be admitted to the hospital but less likely to need admission in a high level of care ward. The false -negative rate increased from March to May. Conclusion: False-negative RT-PCR COVID-19 patients present a similar spectrum of symptoms compared with positive cohort, but more comorbidities. Imaging helps to identify them. True positives had a higher risk of serious complications. (c) 2021 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

Automated summary

This study aimed to compare patients who initially tested negative for COVID-19 with those who tested positive in terms of clinical presentation, laboratory results, imaging findings, and prognosis. Results showed that patients with negative initial tests tended to have more comorbidities such as heart disease, immunosuppression, and diabetes, and imaging was useful in identifying them. True positive patients had a higher risk of serious complications.