Guidelines for the evaluation of instruments used in haematology laboratories.

Instruments have to undergo evaluation at three levels. Firstly, the manufacturer has to evaluate in order to produce data on which to base performance claims-for example, for inclusion in sales literature or for submission to a regulatory authority, such as the Food and Drug Administration in the USA. Secondly, evaluation is done on behalf of would-be users by laboratories acting for government departments and organisations such as the British Committee for Standardisation in Haematology and the College of American Pathologists. At this level, among other things, the evaluator seeks to validate the manufacturer's performance claims and look for inherent hazards in use. Thirdly, the would-be user evaluates whether a particular instrument-rather than the one tested elsewhere-is reliable and whether the special requirements of his own laboratory are met. In doing this he takes account of sample volume, workload and range of pathological states usually encountered. The International Committee for Standardisation in Haematology (ICSH): "Protocol for type testing equipment and apparatus for haematological analysis"' provides general guidance for manufacturers. Shinton et a12 have described a protocol for evaluation of coagulometers. Broughton et al3 have recommended a scheme for the evaluation of instruments for use in clinical chemistry laboratories and Percy-Robb et a!4 have recommended a scheme for the evaluation of kits in the clinical chemistry laboratory. The object of this paper is to provide general guidance and a systematic approach, to meet haematological requirements, for evaluation at the second and third levels. The principles outlined are common to the evaluation of a wide range of instruments and should be generally applicable to reagents and kits as well. The principles should enable the evaluator to adapt a protocol specifically for his own requirements. Appendix 2 is a protocol