External Quality Assessment and Proficiency Testing in Diagnostic Molecular Microbiology

Abstract

Proficiency testing (PT) and external quality assurance/assessment (EQA) are considered interchangeable terms; the generally accepted international terminology is ‘‘proficiency testing,’’ which is used in this chapter. The requirement for PT, as discussed in the chapter, applies to the Centers for Medicare and Medicaid Services (CMS)-accredited laboratories and pertains to nonwaived testing. Laboratory-specific aspects of the protocols should include detailed information regarding specimen evaluation, methods and reagents used for sample reconstitution and testing, maximum interval between reconstitution and testing, storage of excess sample, documentation. In order for PT to be relevant to the quality of patient care testing, PT challenge specimens must be tested in the same manner as patient specimens, including the processing, method and extent of testing, and personnel assigned to perform the testing. Among the microbiology surveys, there are pathogen-specific surveys specifically challenging molecular diagnostic strategies, including qualitative detection and identification, quantification, and genotyping. Proficiency testing, along with other Clinical Laboratory Improvement Amendments (CLIA) quality requirements, provides laboratories and accreditation organizations the tools needed to assess and improve the quality of diagnostic testing. The collaborative efforts of external advocacy groups, professional organizations and societies, governmental and nongovernmental agencies, and commercial providers of quality assurance products should result in increasing improvements to the technical quality and clinical utility of molecular diagnostic testing for infectious diseases. These improvements should result in improvements in patient safety and clinical outcomes as well as the efficiency of diagnostic testing for laboratories and health care systems.