Evaluation of 30 commercial assays for the detection of antibodies to HIV in China using classical and Bayesian statistics

The purpose of this study was to evaluate the 30 commercial HIV-antibody (HIV-Ab) assays in the nationwide assessment program of China using classical and Bayesian statistical methods. The classical estimates of sensitivity and specificity varied from 95.9% to 100% and from 94.6% to 100%, respectively. The proportions of assays with 100% sensitivity and with 100% specificity reached 63.3% (19/30) and 3.3% (1/30), respectively. Using the Bayesian logit hierarchical model, the overall estimates of sensitivity and specificity were 99.8% (95% Bayesian credible interval [BCI]: 99.4-100%) and 98.1% (95% BCI: 97.4-98.7%), respectively, for the 17 ELISAs under evaluation. For the 13 rapid assays, the corresponding overall estimates were reported to be 99.2% (95% BCI: 98.5-99.8%) and 98.4% (95% BCI: 97.8-98.9%), respectively. In addition, given the prevalences of HIV infection among the general population of China and the intravenous drug user group in China, the positive predictive values were estimated for each individual assay in the framework of the two schools of statistical thought. Furthermore, by comparing the two types of estimates, it is concluded that the two types of statistical methods were complementary for the evaluation of very accurate HIV-Ab assays.