Title: Are antibodies tests accurate? Visualizations of predictive values and uncertainty of SARS-CoV-2 serology tests

Abstract:

Antibodies testing in the coronavirus era is frequently promoted, but the underlying statistics behind their validation has come under scrutiny. We provide calculations, interpretations, and plots of positive and negative predictive values under a variety of scenarios. Prevalence, sensitivity, and specificity are estimated within ranges of values from researchers and serology test manufacturers. Illustrative examples are highlighted, and interactive plots are provided in the Supplementary Material. Implications are discussed for society overall and across diverse locations with different levels of disease burden. Specifically, the proportion of positive serology tests that are false can differ drastically from up to 3% to 88%

for people from different places with different proportions of infected people in the populations while the false negative rate is typically under 10%. Data and code are available on our github repository.