With More SARS-CoV-2 Tests, More Focus on Test Characteristics Also Needed
In a recent Insights article published in JAMA Health Forum, Drs. Leah Marcotte and Joshua Liao argue for greater focus on, and incorporation of, testing characteristics in SARS-CoV-2 testing policies.
As Drs. Marcotte and Liao note:
"Amid the ongoing coronavirus disease 2019 (COVID-19) pandemic, the issue of diagnostic testing has been front and center. Testing capacity has been woefully insufficient for clinical testing of high-risk individuals, much less for epidemiologic evaluation of prevalence, community spread, and the consequences of public health interventions, such as social and physical distancing, school closures, and geographic shutdowns. We need more testing capacity.
However, missing from this intense focus on testing appears to be a discussion of test characteristics including sensitivity, specificity, and diagnostic yield. Information about sensitivity is critical for understanding the risk of false-negatives in the context of community transmission and variable clinical symptoms. By providing insight into false-positives, test specificity also poses implications for how policy makers understand the true scope of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). No test is ironclad, and thoughtful approaches require considering the limitations of whatever testing capacity is created."
By highlighting the need to be better incorporate test characteristics into SARS-CoV-2 testing policies, Drs. Marcotte and Liao argue for several overarching priorities:
Dissemination of Test Characteristics and Yield Information. Data about characteristics (sensitivity, specificity, PPV, NPV) should be prioritized and made widely available ASAP for incorporation into national and local testing policies.
Recognition of Potentially Poor Yield or Test Performance. Poor yield or test characteristics pose implications for testing in both health care settings (e.g., using test results to change care decisions) and the community (using test results to determine when/how to relax social distancing measures). Testing policies should acknowledge these issues while testing new methods for improving upon them.
Balance Between Patient Care and Clinician Safety. The balance between diagnostic benefits and workforce safety is likely to vary by clinical scenario. Testing policies should weigh this balance.