By - June 16, 2021
In the April issue of Critical Values, ASCP identified our first two targeted, evidence-based recommendations for COVID-19 (SARS-CoV-2) testing. In April 2021, the ASCP Effective Test Utilization Committee, continuing its collaboration with the ASCP Commission on Science, Technology and Policy added another two recommendations, bringing our COVID recommendation total to four.
COVID-19 testing guidelines are rapidly changing, and the goal in developing and making all four recommendations publicly available is to assure the broader medical community and our patients receive appropriate tests. Given rapid advancements in this emotionally charged diagnostic area, we continue to see situations where patients are tested using strategies that are not optimal for the diagnosis and treatment of their conditions.
The two new recommendations address issues in the testing management of asymptomatic patients: specifically, how to handle patients with positive antigen tests and the use of respiratory viral panels in patients without signs or symptoms of COVID-19.
The first new recommendation advises when antigen tests are used to evaluate asymptomatic patients, positive results should be confirmed using a RT-PCR method.1
ASCP acknowledges the high specificity of many antigen tests yet the positive predictive value remains low when used to test asymptomatic patients. When the pretest probability of infection is low, then false positives will represent a higher percentage of all positive results, so ASCP recommends confirmation of positive results using a RT-PCR method, which is consistent with guidance from the CDC.1
The second new recommendation advises against ordering a respiratory viral panel (ie, SARS-CoV-2 and other pathogens) for COVID-19 screening to evaluate asymptomatic patients following possible exposure or for return to work/school.2
Limited respiratory pathogen panels (eg, SARS-CoV-2, influenza) have recently become available to evaluate symptomatic patients for possible COVID-19 infection. These panels are appropriate for evaluating symptomatic patients when the pathogens in the panel are part of the differential diagnosis. However, when evaluating asymptomatic patients for possible COVID-19 infection (eg, exposure, return to work, pre-flight), only the SARS-CoV-2 antigen or RT-PCR test is medically necessary.
ASCP hopes that recommendations will continue to enhance the dialogue between pathologists and laboratory professionals, clinicians and patients. For a list of all four recommendations, visit www.ascp.org/COVID-19.