Practices and Perceived Value of Proficiency Testing in Clinical Laboratories

Background: Proficiency testing (PT) can have regulatory and nonregulatory uses, providing an effective tool for quality improvement. Clinical laboratories were surveyed to determine how they perceive PT and how they use PT results and materials to improve laboratory testing quality. Methods: All laboratories certified to perform nonwaived testing under the CLIA regulations expected to perform required PT were invited to participate in the survey. We examined respondents' use of PT from 5 laboratory types: hospital, independent, public health, physician office, and "all other." Respondents' awareness of resources about PT was also examined. Several questions allowed responses on a categorical scale. Results: Varying proportions of the respondents (n = 769) used PT to identify problems in the preanalytic (48%), analytic (86%), andpostanalytic (76%) phases of testing. Responses also showed that PT was important for demonstrating personnel competency (93%), inappropriate specimen handling (80%), incorrect result interpretation (84%), and other uses. Respondents purchased PT even when not required to do so (77%). Based on all responses, most considered PT worth the cost (65%). Conclusions: Laboratories, regardless of type, have found ways of using leftover PT samples and the information from PT event summaries to help improve laboratory quality. Our findings suggest many laboratories are not taking full advantage of PT to improve testing quality. Additionally, the study suggests a need to improve awareness of resources about PT.