Upsala J Med Sci 95: 275-277, 1990 Plans for Obtaining a “NORDIC LIST” of Specifications Carl-Henric de Verdier Department of Clinical Chemistry, University of Uppsala, Uppsula, Sweden In several countries work is going on in order to establish numerical values for quality specifications for clinical chemical (and haematological) analyses and investigations. In some countries this work is connected with proficiency testing organized by a controlling authority or a professional society as proficiency test must have specified rules for approval ( 2 , 4 ) . In the Nordic countries several different programs for external quality assurance have been running (1). What is acceptable quality is, however, left to the head of the laboratory - as a head physician - to decide. New trends within laboratory medicine with more decentralized laboratories, more economical responsibility delegated to the laboratory and more competition between laboratories call for guidelines for quality specifications. This new attitude has also influenced the new Scandinavian Recommendations for Quality Control and Quality Assurance (5) as indicated in the third chapter of this report. CONSIDERATIONS IN THE PREPARATION OF A NORDIC LIST The Board of the Nordic Clinical Chemistrv Droiect (NORDKEM) has earlier and in the preliminary work for this project expressed its wish to let the professionals of the clinical laboratories, the doctors in primary care and the clinicians prepare a list of quality specifications. A lot of questions must be ventilated in connection with the preparation of such a list. Table 1 presents a checklist which might be of value when preparing a list of quality specifications for the Nordic countries. 275 Table 1. Checklist for the preparation of a Nordic list of quality specifi- cations for clinical chemical laboratories. The list of quality specifications must be structured around: System--Component, Testing/evaluation of different methods/investigations Clinical situations (concentration ranges) Type of quality specification: 1) Clinical Needs 2) Clinical Quality Specifications 3 ) Analytical quality goals (TE,) and in the local laboratory 4 ) Laboratory Quality Specifications (see more in chapter 3, Fig. 1). The expression of the quality specifications. The 95 % probabil- ity range within which results of investigations should be localized. Starting from the analytical side that means e g (where the abbreviations have the following meaning: TE, total allowable error = AAE, SE, critical systematic error expressed as a factor times s , RE, critical random error and s inherent random imprecision). Starting from the side of clinical needs that means e g TE, = bias + SE,.s + [component of RE,] A > d?. . 1.65 (CV,’ + CV,’ + CV,’)” ( 3 ) (where CV means coefficient of variation, B within-individual, P pre-analytical and A analytical sources of variation; 0 is an significant difference in serial results during a monitoring situation). Also other ways of calculating clinical needs and clinical quality specifications - using e g decision analysis or biomedical models (see chapter 3 ) - are of interest. In accordance with “International Vocabulary of Basic and General Terms in Metrology” (VIM) (6) and other relevant standards and guidelines. * Complementation with matrix effects (specified) and unspecific reactions (specified). Existing guidelines for the measurement of such effects should be improved. 276 * * 1. Presentation of the list in a standardized form and possibly also as a data base. Which components should be included? Primarily the 40 most frequently analyzed components and some more analytes of principal interest. Only investigations that have a significant role in the clinical process. Evaluation of the list with quality specifications? Submission to the Scand J Clin Lab Invest and to the Newsletters of the national societies of clinical chemistry in Scandinavia and of the Nordic Society of Clinical Chemistry? Sending draft for consideration to the national Societies for Clinical Chemistry in the Nordic countries? Discussion at the next Nordic congress in 1992? REFERENCES In de Verdier C-HI Aronsson TI Nyberg A: (eds): Quality Control in Clinical Chemistry - Efforts to Find an Efficient Strategy, Helsinki, NORDKEM, 1984, p 1-241 2. Ehrmeyer SS, Laessig RH. Use of alternative rules (other than the 1 2s) for evaluating interlaboratory performance data. Clin Chem (1988);34:250-256. 3. Fraser CG, Hyltoft Petersen PI Larsen ML. Setting analytical goals for random analytical error in specific monitoring situ- ations. Clin Chem (1990);36:1625-1628. 4. Laessig RH, Ehrmeyer SS. Use of computer modelling to predict magnitude of interlaboratory error tolerated by proposed CDC interlaboratory proficiency testing performance criteria. Clin Chem 5. Scandinavian Society for Clinical Chemistry. General Scandina- vian Recommendation on Quality Control an Quality Assurance in Clinical Chemistry. Scand J Clin Lab Invest (1990);50:225-227. 6. Zender R. Measurements in Biological Systems. Metrological Principles and Terminology. Scand J Clin Lab Invest (1989);49 suppl (1988);34:1849-1852. 193 : 3-10. Correspondence: Professor Carl-Henric de Verdier Department of Clinical Chemistry, Uppsala University Postal address: University Hospital S-751 85 Uppsala, Sweden. 277