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Quality assurance in laboratory haematology

Published online by Cambridge University Press:  05 December 2011

S. M. Lewis
Affiliation:
Department of Haematology, Royal Postgraduate Medical School, London
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Synopsis

Quality assurance in laboratory haematology includes (a) constant checking of test reliability by internal quality control, (b) external quality assessment by an independent agency to check performance of a number of laboratories at intervals in order to obtain a retrospective indication of their ability and (c) proficiency control by supervision of the pre-test and post-test phases of laboratory work, from specimen collection to delivery of the report to the clinician.

The procedures which comprise quality control are described; these include use of control preparations with control charts, CUSUM analysis, constancy of daily means of the blood count indices of ‘absolute values’, duplicate testing, clinical correlation and the important role of the blood film to check the instrument-derived blood count measurements.

A description of the functions of an external quality assessment scheme is based on the UK National Scheme (UK NEQAS). The blood count and other tests of general haematology have been used as models to describe the procedures for qualitative and quantitative tests, low results are analysed and performance is assessed. The tribulations and triumphs of NEQAS are described and it is concluded that NEQAS has a vital role in ensuring good laboratory practice in general, and the reliability of the individual laboratories who participate in the scheme. NEQAS, in turn, must ensure its own ability to provide stable materials which are suitable for each test in the programme, and to analyse data correctly. There is also need to take account of the continued expansion of laboratory services as new techniques are introduced and to develop appropriate EQA procedures and materials in order to incorporate these in a comprehensive scheme.

Type
Research Article
Copyright
Copyright © Royal Society of Edinburgh 1993

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References

Belk, W. P. & Sunderman, F. W. 1947. A survey of the accuracy of chemical analysis in clinical laboratories. American Journal of Clinical Pathology 17, 853–61.CrossRefGoogle Scholar
Bull, B. S., Elashoff, R. M., Heilbron, D. C. & Couperus, J. 1974. A study of various estimators for the derivation of quality control procedures from patient erythrocyte indices. American Journal of Clinical Pathology 61, 473–81.CrossRefGoogle ScholarPubMed
Coster, J. F. 1964. Results of international haematological trials. Bibliotheca Haemalologica 18, 92101.Google ScholarPubMed
Dacie, J. V. & Lewis, S. M. 1991. Practical haematology, 7th Edn, pp. 61–3, 7585. Edinburgh: Churchill Livingstone.Google Scholar
Eilers, R. J. 1975. Principles of total quality control. In Lewis, S. M. & Coster, J. F. (Eds) Quality control in haematology, pp. 112. London, Academic Press.Google Scholar
Healy, M. J. R. 1979. Outliners in clinical chemistry quality control schemes. Clinical Chemistry 25, 615–7.CrossRefGoogle Scholar
Hoffmann, R. G. & Waid, M. E. 1963. The number-plus method of quality control of laboratory accuracy. American Journal of Clinical Pathology 40, 263–9.CrossRefGoogle Scholar
International Committee for Standardization in Haematology (Expert Panel on Iron). 1985. Proposed international standard of human ferritin for the serum ferritin assay. British Journal of Haematology 61, 61–3.CrossRefGoogle Scholar
International Council for Standardization in Haematology. 1992. Guidelines for reticulocyte counting by microscopy on supravitally stained preparations. WHO Document LBS/92·3. Geneva: World Health Organisation.Google Scholar
International Federation of Clinical Chemistry/International Committee for Standardization in Haematology. 1987. Approved recommendation (1986) on the Theory of Reference Values. Part I. The concept of reference values. Journal of Clinical Chemistry and Clinical Biochemistry 25, 337–42.Google Scholar
Koepke, J. A. 1986. The College of American Pathologists Survey programme. In Rowan, R. M. & England, J. M. (Eds) Automation and quality assurance in haematology, pp. 6283. Oxford: Blackwall Scientific Publications.Google Scholar
Korpman, R. A. & Bull, B. S. 1976. The implementation of a robust estimator of the mean for quality control on a programmable calculator or laboratory computer. American Journal of Clinical Pathology 65, 252–3.CrossRefGoogle ScholarPubMed
Lamb, A. A., Matteliano, S. & Freedman, J. J. 1991. Detection of abnormal haemoglobins by the Sysmex NE-8000 automated cell counter. British Journal of Haematology 77, 567–8.CrossRefGoogle ScholarPubMed
Lewis, S. M. 1975. Standards and reference preparations. In Lewis, S. M. & Coster, J. F. (Eds) Quality control in haematology, pp. 7995. London: Academic Press.Google ScholarPubMed
Lewis, S. M. 1988. External quality assessment. In Lewis, S. M. & Coster, J. F. (Eds) Quality assessment in haematology, pp. 151–75. London: Balliere Tindall.Google ScholarPubMed
Lewis, S. M. & Burgess, B. J. 1969. Quality control in haematology: report of the interlabortory trials in Britain. British Medical Journal 4, 253–6.CrossRefGoogle Scholar
Lewis, S. M. & Sanders, K. J. 1989. Screening for G-6-PD by Sigma kits. Clinical Laboratory Haematology 11, 76–8.CrossRefGoogle Scholar
Leyssen, M. H. J., De Bruyere, M. J. G., Van Duppen, V. J. M. & Verwilghen, R. L. 1985. Problems related to CPD preserved blood used for NEQAS trials in haematology. Clinical Laboratory Haematology 7, 239–43.CrossRefGoogle ScholarPubMed
McVeigh, D. J. & Van der Weylen, M. B. 1989. Correction of spurious haematological results using Technicon H1-derived data. Clinical Laboratory Haematology 11, 369–73.CrossRefGoogle Scholar
Pantalony, D., Wood, D. & Jacobs, W. 1986. Proficiency testing in hematologic morphology – a ten year experience. XXI Congress of International Society of Haematology, Sydney (Abstracts) 250.Google Scholar
Reardon, D. M., Mack, D. & Hutchinson, D. 1991. A whole blood control for blood count analysers, and source material for an external quality assessment scheme. Medical Laboratory Sciences 48, 1926.Google ScholarPubMed
Solanki, D. L. & Blackburn, B. C. 1985. Spurious red blood cell parameters due to serum cold agglutinins: observations on Ortho ELT-8 cell counter. American Journal of Clinical Pathology 83, 218–22.CrossRefGoogle ScholarPubMed
Stewart, J. W., Crossland-Taylor, P. J., Carter, A. B. & Barnard, D. F. 1972. Quality control of fully automated blood counters. In Izak, G. & Lewis, S. M. (Eds) Modern concepts in haematology, pp. 213–16. New York: Academic Press.Google Scholar
Tukey, J. W. 1977. Exploratory data analysis. Boston: Addison-Wesley.Google Scholar
Ward, P. G., Chappell, D. A., Fox, J. G. C. & Allen, B. V. 1975. Mixing and bottling unit for preparing biological fluids in quality control. Laboratory Practice 24, 577–83.Google ScholarPubMed
Wardle, J., Ward, P. G. & Lewis, S. M. 1985. Response of various blood counting systems to CPD-AI preserved whole blood. Clinical Laboratory Haematology 7, 245–50.CrossRefGoogle Scholar
Weiss, G. B. & Bessman, J. D. 1984. Spurious automated red cell values in warm autoimmune hemolytic anaemia. American Journal of Hematology 17, 433–5.CrossRefGoogle Scholar
White, J. M. & Lewis, S. M. 1973. A report on the interlaboratory quantitation of haemoglobin A2 and haemoglobin F. Journal of Clinical Pathology 26, 864–67.CrossRefGoogle ScholarPubMed
Whitehead, T. P. 1977. Quality control in clinical chemistry, pp. 95105. London: John Wiley.Google Scholar
Youden, W. J. 1960. The sample, the procedure and the laboratory Analytic Chemistry 32, 2337.CrossRefGoogle Scholar