Ryhmänäytteenotto

Ryhmänäytteenotto, also known as group testing or pooled sampling, is a method of statistical sampling where individual samples are combined into groups before being tested. This technique is particularly useful when the prevalence of a certain characteristic or defect within a population is low. The primary goal of ryhmänäytteenotto is to reduce the number of individual tests required, thereby saving time and resources.

In a typical ryhmänäytteenotto process, a number of individual samples are pooled together to form a single group sample. This group sample is then subjected to a diagnostic test. If the test result for the group sample is negative, it can be concluded that all individual samples within that group are also negative. This single test effectively screens multiple individual samples. However, if the group sample tests positive, it indicates that at least one individual sample within the group is positive. In such cases, further testing is required to identify the specific positive individual samples, often through re-testing each sample individually or by employing more sophisticated subdivision methods.

The effectiveness of ryhmänäytteenotto depends on the size of the groups and the prevalence of the characteristic being tested. Larger group sizes lead to greater cost savings but also increase the probability of a positive group test, requiring more follow-up individual tests. Therefore, an optimal group size needs to be determined based on the specific application and the expected prevalence rate. Ryhmänäytteenotto has found applications in various fields, including public health (e.g., screening for infectious diseases like HIV or COVID-19), quality control in manufacturing, environmental monitoring, and DNA analysis.