Issues in COVID-19 research and statistical analyses (Part XVIII) At home Antigen tests statistical results November 24, 2021
Antigen tests for SARS-CoV-2 are back and are pending more approvals by the current administration. If so, they may be used more often and more frequently to help people get back to a more normal lifestyle. The question here is what or where are the result for such tests. In an article by Harmon et al (2021) that appeared in JAMA Open Network on August 27, 2021 to test the sensitivity and specificity of at-home antigen tests, specifically of direct antigen rapid tests (DART), their analysis used a generalized estimating equation with a independence correlation structure. The mention the use of the correlation structure due to having clusters of multiple tests per individual. They utilized 2-sided binomial Clopper-Pearson methods for calculating the confidence intervals of the sensitivity and specificity during days 0 to 7 of symptoms when there was at least 1 test per individual. We can assume the outcome is the disease status coded as a binary outcome. The working correlation matrix seems to work well for clustered data. They then stated that the sensitivity of DART within days 0 to 12 of symptom onset was 78.9% (60 of 76 swabs; 95% CI, 69.1%-88.8%), and the specificity of DART was 97.1% (2791 of 2875 swabs; 95% CI, 96.3%-97.8%). The