Westgard

Westgard is a surname associated primarily with James O. Westgard, an American clinical chemist who co-developed a systematic approach to quality control in laboratory testing. The most enduring contribution bearing the Westgard name is the set of quality control rules known as the Westgard Rules. These rules provide multi-rule criteria applied to control measurements to determine whether an analytical run is in control. Common components include the 1-2S and 2-2S rules for detecting random and systematic errors, as well as 4-1S and 10x rules for flagging larger deviations and run-length issues. The Westgard Rules are used with control charts and are widely taught and implemented in clinical laboratories to monitor accuracy and precision of assays.

In addition to the QC framework, Westgard QC is a company focused on laboratory quality management. It provides quality control products, software, and training materials intended to help laboratories implement and audit QC procedures consistent with the Westgard Rules. The Westgard framework and resources have been influential in laboratory medicine, encouraging standardized QC practices and the use of multi-rule decision making to improve error detection and patient safety.