Cholesterol--a model system to relate medical needs with analytical performance.

The evolution of cholesterol testing provides an example of a systematic approach that developed to relate the medical use of a laboratory test with the analytical performance requirements for that test. Laboratories today have the capability to perform cholesterol testing with the accuracy and precision necessary to meet medical needs. This statement can be made because (a) a standard diagnostic process has been established by the National Cholesterol Education Program; (b) an accuracy base is provided through a reference method that is readily available to manufacturers and laboratories; (c) the precision of analytical systems has been improved by manufacturers; (d) operating specifications for all such systems can be established, with statistical quality-control rules to ensure adequate within-run method performance; and (e) analytical performance is monitored by proficiency testing by using national quality requirements defined by CLIA '88 for acceptability. This cholesterol model provides a logical and scientific approach that should be applicable with other analytes to assure that the analytical performance of the laboratory test satisfies medical needs.