Pooled or group testing is a testing strategy where samples from a number of individuals are aggregated into a single sample (or pool), which is then tested for the disease or agent of interest. Pooled testing strategies have been proposed for identification of infected individuals (classification), for demonstration of herd or area infection status and for estimation of prevalence of infection.
The utilities provided on this web-site are designed to assist with the estimation of prevalence from the testing pof pooled samples. When used for this purpose, individual samples are aggregated into pools for testing. Individual-level prevalence is then estimated based on the number of individuals represented in each pool and the test result for that pool. Estimation methods are provided for both fixed and variable pool size and to adjust estimates for imperfect sensitivity and specificity of the test used.
Pooled testing has some significant advantages over individual testing. In particular, pooled testing provides:
Pooled testing strategies also have a number of disadvantages, including:
Additional utilities are also provided for the estimation of true prevalence based on testing of individual samples (unpooled) using either one or two tests of inperfect and uncertain sensitivity and specificity. These utilities use Bayesian methods to account for uncertainty about the true values of sensitivity and specificity for the test(s) used.
|3||Bayesian vs Frequentist methods|
|4||Fixed pool size and perfect tests|
|5||Fixed pool size and known Se & Sp|
|6||Fixed pool size and uncertain Se & Sp|
|7||Variable pool size and perfect tests|
|8||Pooled prevalence using a Gibbs sampler|
|9||True prevalence using one test|
|10||Estimated true prevalence using two tests with a Gibbs sampler|
|11||Estimation of parameters for prior Beta distributions|
|12||Sample size for fixed pool size and perfect test|
|13||Sample size for fixed pool size and known test sensitivity and specificity|
|14||Sample size for fixed pool size and uncertain test sensitivity and specificity|
|15||Simulate sampling for fixed pool size|
|16||Simulate sampling for variable pool sizes|
|18||Pooled prevalence estimates are biased!|