PROFICIENCY TESTING SCHEMES; CHALLENGES IN HARMONIZATION

Proficiency Testing Schemes (PTS) are not universally harmonized. Schemes developed for clinical laboratories differ from those developed for food testing laboratories. Environmental PT Schemes differ from those used for industrial hygiene testing. Moreover, even within an industry such as Environmental Proficiency Testing, there are regional, national and international differences that culminate in a lack of harmonization. When examining the purposes and common uses for proficiency testing, it becomes clear that the lack of consistency between different PTS negatively affects a lab's ability to achieve their expected goals. An understanding of the reasons for the differences in PTS and exploring opportunities for increasing harmonization between schemes is critical to supporting the many valuable uses for PT. While some of the PTS differences stem from true technical dissimilarity among the markets and analytical procedures being evaluated, there are also political, financial, and regulatory influences that drive programmatic differences. This paper will provide a review of a sample of different schemes and highlight differences and similarities followed by a discussion of the challenges and impacts of harmonization.