The performance of the knowledge-based system VALAB revisited: an evaluation after five years

In 1988, inundated by the tedious work of validation of laboratory reports in a large hospital biochemistry laboratory, we designed VALAB, a knowledge-based system specially dedicated to this iterative function. Coping at first with a few biochemical tests, the program has been progressively expanded to forty-five common chemical tests. Simultaneously some new rules have been introduced to "weight" the conclusion in different circumstances and rules taking into consideration some clinical data have also been written. Moreover the program moved to other disciplines, pH and blood gases, haematology and coagulation. Accordingly the evaluation protocol has been modified, incorporating a new step, the consensus decision of the pathologists, operating within the initial protocol and based upon the various criteria of epidemiology. These major changes and improvements have led us to check and describe again the performance of this updated VALAB knowledge-based system.