Harmonization of External Quality Assessment Schemes and their role - clinical chemistry and beyond

The article tries to reply to the following three questions: Are External Quality Assessment Schemes (EQAS) really fit for purpose? Are all schemes equivalent and sufficiently harmonized? Is the role of EQAS similar and necessary in all branches of laboratory medicine? Although the reply to the first two questions is, unfortunately, negative for several reasons (lack of commutable material with reference method values, EQAS with different scopes, etc.), the reply to the third one is positive: EQAS are a necessary source of information on trueness and accuracy and must be fully developed for all the branches of the clinical laboratory.