Assessing the Analytical Quality of the Clinical Laboratory

The clinical laboratory services of the UK National Health Service (NHS) is the fastest growing expenditure area of the Service. The clinical chemistry services are probably the largest of the disciplines making up the clinical laboratory service regarding workforce, workload and expenditure. In the early years of the NHS there was evidence of poor analytical performance by the clinical chemistry laboratories. This was shown by external quality assessment (EQA) techniques. By continuous and frequent use of EQA where portions of the same material are sent to over 400 laboratories and analyses compared it has been shown that the analytical performance has considerably improved. The reasons for this are probably the adoption of methods shown to perform well on EQA and also the widespread use of internal quality control techniques. The difficulties of providing appropriate material for EQA and the method of dealing with poor performance are also discussed.