Establishing the Accuracy of RNA polymerase Chain Reaction Tests in Symptomatic SARS-Cov-2 Patients with Predictive Values

Melnick PJ, Glatt AE, Friedman D and Kaminetzky JS

Published on: 2020-11-05


Background: High accuracy testing for the novel SARS-CoV-2 serves a vital resource in preventing the continued spread of the virus. However, reports of false-negatives from the test undermine the public health effort to contain the virus as it promotes carelessness in adhering to safety measures. The extent to which false-negatives is an issue needs to be assessed.

Objectives: The objective of the study to assess whether RT-PCR testing of the SARS-CoV-2 serves as a reliable method of guiding patients in preventing the spread of COVID-19. In addition, the role of patient sex was explored as a potential source inaccuracy in the tests.

Methods: 141 symptomatic patients were tested for SARS-CoV-2 using RT-PCR testing and followed up at least 14 days later for an IgG-Antibodies test, which served as a gold-standard to assess the accuracy of the initial RT-PCR test. Calculations of positive and negative predictive values were conducted and were assessed for significant differences between sexes.

Results and Conclusions: The total negative predictive value (NPV) was 0.68 while the total positive predictive value (PPV) was 0.96. The Male NPV and PPV were 0.56 and 0.95, respectively. The female NPV and PPV were 0.76 and 0.96. A two-sided t-test between the male and female NPV reveals a P-Value of <0.001, which is significant at P=0.05. Based on high rates of false negatives, particularly amongst men, practices that prevent the spread of COVID-19 should be practiced based on symptom-presence in spite of a negative RT-PCR test.