[OPS-301/ICPM: experiences and problems]

For over 2 years, the classification of procedures OPS-301 has been uniformly used in all German hospitals. The ICPM in German extension has 5-6 digits and is totally compatible with the OPS-301 restricted to operations. This ICPM is qualified for scientific documentation beyond efficiency control. The OPS-301 needs some better representation and some extensions proposed by medical experts. A program that searches for invalid code numbers and uses the relations of OPS-301 to sex, age, and department in a knowledge base, detects a 10% error rate in manual coding with OPS-301. A coding program reduces them to 1.4%. After mapping the OPS-301 by SNOMED this monohierarchical classification becomes multihierarchical. This is advantageous for coding and retrieval.