Diagnostic accuracy of rapid antigen tests in asymptomatic and presymptomatic close contacts of individuals with confirmed SARS-CoV-2 infection: cross sectional study
A study of close contacts illustrates why intended-use populations and testing time must be defined together.
What the paper explores
This cross-sectional study assessed rapid antigen testing in asymptomatic and presymptomatic close contacts of people with confirmed infection. Diagnostic sensitivity changed when the analysis considered subsequent symptoms or used a viral-load threshold as a proxy for infectiousness.
How to interpret the evidence
A viral-load threshold is a proxy, not a direct measurement of transmission. Findings from close contacts tested at a defined point after exposure do not establish accuracy for every screening use.
Questions for MedTech teams
Plan separate analyses for the intended clinical question. Detecting any infection and identifying a high viral-load subset are different evaluation targets.
Sources & further reading
Read original paperDOI: 10.1136/bmj.n1676
Bibliographic record and abstract on PubMedThis is a short editorial reading note on external research. The original research is attributed to its authors and does not represent an HMC study, product validation or regulatory determination.
