[Quality assurance in clinical laboratory diagnosis]

Both the internal and the external quality controls are necessary to achieve reliable and comparable laboratory tests. The internal quality control includes preanalytical, analytical and postanalytical checking of factors to eliminate all interferences of laboratory tests. The use of reliable methods which result in a good accuracy and precision, however, can provide results which are not comparable to the results of other laboratories. The role of the external quality control is to check differences between the laboratories and to make the results as comparable as possible. The accuracy and precision of Hungarian laboratories improved during the past decade which can be attributed to the better technical conditions, on the one hand, and to the regular internal and external quality control, on the other hand. An increasing number of the small laboratories, mostly in the service of general practitioners, are unable to perform the same quality of laboratory tests as that of the central laboratories, since their technical conditions are old-fashioned and inadequate to use up-to-date methods. The urgency of improvement in technical condition of small laboratories is obvious from both professional and economical reasons.