Quality assurance, quality control and quality assessment are defined and their relationships explained. The sometimes overlooked but essential subject of pre-analytical quality is also presented. The principles and practice of internal quality control are explained in detail, including control charts and decision rules., with examples. Possible causes of poor internal quality control performance are listed. The management of external quality assessment schemes is extensively covered, with examples from one of the UK national schemes. The challenges associated with external quality assessment of point-of-care programs are described.

Dr. Catherine M. Sturgeon is the Director of the UK National External Quality Assessment Schemes (Edinburgh), focusing upon Peptide Hormones, Pregnancy Testing and Tumor Markers. She is Clinical Scientist at the Department of Clinical Biochemistry, Royal Infirmary of Edinburgh. Born in South Africa, her pre-University education was in the US before entering the University of Birmingham (UK) where she received her BSc and PhD. Postdoctoral studies in the USA at the University of Miami School of Medicine and a Research Fellowship at the Department of Clinical Chemistry, University of Edinburgh (UK) were followed by her appointment as Senior Biochemist at the Royal Infirmary, Edinburgh, with promotion to her present post of Clinical Scientist in 1997. In 2000, she gained Membership of the Royal College of Pathologists. Dr Sturgeon has contributed to the purification and standardisation of Human Chorionic Gonadotropin and to the characterisation of antibodies directed against the hormone. Her work on tumour markers led to her appointment as Vice-Chair of the National Academy of Clinical Biochemistry’s Panel on Laboratory Medical Practice Guidelines for Tumour Markers. Dr Sturgeon is the author of 63 papers.

Quality, quality assurance, quality control, quality assessment, quality specifications, pre-analytical, sample collection, sample storage, controls, precision, control charts, Levey-Jennings, Cusum, Westgard rules, point-of-care.