Basics of laboratory statistics.

The strict monitoring of examinations and evaluation of newer methods or instruments is a daily routine in clinical laboratory. The automated analyzers accumulate an enormous amount of data from patients' examinations and quality control procedures. This laboratory data is meaningless if it does not generate the information that we can extend to the population of our interest. In an analytical work, the most important operation is the comparison of data, to quantify accuracy and precision and to generate meaningful explanation for clinician and patients queries. Most of the information needed in the regular laboratory work can be obtained with the use of simple convenient statistical tools. This article describes the basics of laboratory statistics, the knowledge of which answers about the application of quality control in laboratory, accuracy and diagnostic power of our examinations, variability in reports, comparison of different methods and derivation of a biological reference interval for an analyte.