To review tenets of basic quality assurance and identify opportunities for quality improvement in the laboratory assessment of prognostic factors.
College of American Pathologists Q-Probes data obtained from hundreds of American laboratories throughout the 1990s are used to illustrate laboratory performance and practice opportunities in the preanalytic, analytic, and postanalytic phases of the total testing process.
A wide range of performance deficiencies are documented, most in the preanalytic and postanalytic phases, and contributed by individuals outside and not under the control of the laboratory. In the analytic phase, the effectiveness of checklists on the content and completeness of reported diagnostic and prognostic data for breast and colon cancers is proven.
In the preanalytic phase, marked enhancements in quality would result from improvements in (1) patient and specimen identification, (2) adherence to patient-sampling and specimen-handling requirements, and (3) communication to the laboratory of the pertinent clinical context of the individual test. Once basic analytic quality control and laboratory quality assurance issues are resolved, a focus on standardization and enhancement of preanalytic and postanalytic communications and satisfaction of clinical expectations becomes the source of improved laboratory performance.