Coding medical information: classification versus nomenclature and implications to the Israeli medical system.

The efficient retrieval of medical information is essential for all functional aspects of a health system. Such retrieval is possible only by coding data (as it is produced or after it is produced) and entering it into a data-base. The completeness and accuracy of retrieved information depend, therefore, on the coding system employed. The main coding system that is in use in Israel is the ICD-9: International Classification of Diseases and its clinical modification (ICD-9-CM). Using such a statistical classification system for coding has met the basic needs for statistical and administrative purposes, but causes distortion and loss of information. With the recent growth and availability of information technology, more detailed data can be coded and processed than was possible before. A detailed nomenclature system such as SNOMED (the Systematized Nomenclature Of Human and Veterinary Medicine) can be used as a coding system that enables a more comprehensive and flexible medical information data base. This article discusses some aspects of coding medical information and suggests that a national revision of medical coding systems be considered as the computerized-patient-record is further developed and implemented.