ABSTRACT
The purpose of the clinical laboratory is to analyze body fluids and tissues for specific substances of interest and to report the results in a form which is of value to clinicians in the diagnosis and treatment of disease. A large range of tests has been developed to achieve this purpose. Four terms commonly used to describe tests are accuracy, precision, sensitivity, and specificity. An accurate test, on average, yields true values. Precision is the ability of a test to produce identical results upon repeated trials. Sensitivity is a measure of how small an amount of substance can be measured. Specificity is the degree to which a test measures the substance of interest without being affected by other substances which may be present in greater amounts.
