As communities throughout the U.S. have struggled to deal with the consequences of the COVID-19 pandemic, many have centered on the shortage of widespread testing as a significant barrier to securely reopening the nation. As progress has been made on this entrance, concern has shifted to testing accuracy, predominantly with antibody exams, that are designed to determine prior an infection.
However in keeping with a brand new Dartmouth-led paper printed within the New England Journal of Medication, extra emphasis must be positioned on addressing the inaccuracy of diagnostic exams, which play a key position in containing the pandemic.
“Diagnostic exams, usually involving a nasopharyngeal swab, might be inaccurate in two methods,” explains lead writer Steven Woloshin, MD, MS, a professor of drugs and group and household drugs at Dartmouth’s Geisel Faculty of Medication, and of The Dartmouth Institute for Well being Coverage and Scientific Observe. “A false-positive outcome mistakenly labels an individual contaminated, with penalties together with pointless quarantine and phone tracing. False-negative outcomes are much more consequential as a result of contaminated individuals who is likely to be asymptomatic is probably not remoted and might infect others.”
Of their paper, Woloshin and his colleagues talk about elements contributing to the present limitations of diagnostic exams — together with variability in check sensitivity and the shortage of a regular course of for validating check accuracy — and likewise cite a number of giant research whose frequent false-negative outcomes are trigger for concern.
The researchers draw a number of conclusions from their work. “Diagnostic testing will assist to securely open the nation, however provided that the exams are extremely delicate and validated in opposition to a clinically significant reference commonplace — in any other case we can not confidently declare folks uninfected,” says Woloshin.
The FDA also needs to be sure that check producers present particulars of their exams’ scientific sensitivity and specificity on the time of market authorization. Assessments with out such data could have much less relevance to affected person care.
“Measuring the sensitivity of exams in asymptomatic folks is an pressing precedence,” says Woloshin. “A unfavorable outcome on even a extremely delicate check can not rule out an infection if the pretest chance — an estimate earlier than testing of an individual’s likelihood of being contaminated — is excessive, so clinicians should not belief sudden unfavorable outcomes.”
This estimate may depend upon how widespread COVID-19 is the place an individual lives, their publicity historical past, and signs, he says.