International Classification of Diseases, Ninth Revision The International Classification of Diseases, Ninth Revision (ICD-9) is designed to promote international comparability in the collection, processing, classification, and presentation of mortality statistics. This includes providing a format for reporting causes of death on the death certificate. The reported conditions are then translated into medical codes through use of the classification structure and the selection and modification rules contained in the applicable revision of the ICD, published by the World Health Organization (WHO). Selection rules provide guidance for systema- tically identifying the underlying cause of death. Modification rules are intended to improve the usefulness of mortality statistics by giving preference to certain classification categories over others and/or to consolidate two conditions or more on the certificate into one classification category. The ICD has been revised periodically to incorporate changes in the medical field. To date there have been 10 revisions of the ICD. Currently, the United STates uses the Ninth Revision. To help the users of this cd-rom, Volume 1 of the ICD-9 has been placed on this rom in two formats: 1) as part of the SETS software in the documenta- tion section, and 2) as a separate ASCII file in the ICD9 directory. This volume will help the user understand the intricacies of the ICD-9 mortality codes. The file will also let the user search specific ICD-9 codes to facilitate their research. All underlying and multiple cause codes on this rom are contained in ICD-9 Volume 1. - 1 -