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Scientific Data Documentation
International Classification Of Diseases - 9 - CM, (1979)

 Purpose of The ICD-9-CM File
 The International Classification of Diseases, 9th Revision,
 Clinical Modification (ICD-9-CM) is based on the official
 version of the World Health Organization's 9th Revision,
 International Classification of Diseases (ICD-9).  ICD-9
 is designed for the classification of morbidity and
 mortality information for statistical purposes, and for the
 indexing of hospital records by disease and operations, for
 data storage and retrieval.

 This modification of ICD-9 supplants the Eighth Revision
 International Classification of Diseases, Adapted for Use
 in the United States (ICDA-8) and the Hospital Adaptation
 of ICDA (H-ICDA).

 Description of The ICD-9-CM File
 This third edition of the International Classification of
 Diseases, 9th Revision, Clinical Modification (ICD-9-CM) is
 being published by the United States Government in
 recognition of its responsibility to promulgate this
 classification throughout the United States for mobidity
 coding.  The International Classification of Diseases, 9th
 Revision, PUBLISHED BY THE World Health Organization (WHO)
 is the foundation of the ICD-9-CM and continues to be the
 classification employed in cause-of-death coding in the
 United States.  The ICD-9-CM is completely comparable with
 the ICD-9.  The WHO Collaborating Center for Classification
 of Diseases in North America serves as liaison between the
 international obligations for comparable classifications
 and the national health data needs of the United States.

 The ICD-9-CM is recommended for use in all clinical
 settings but is required for reporting diagnoses and
 diseases to all U.S. Public Health Service and Health Care
 Financing Administration programs.

 ICD-9-CM extensions, interpretations, modifications,
 addenda, or errata other than those approved by the U.S.
 Public Health Service and the Health Care Financing
 Administration are not to be considered official and should
 not be utilized.  Continuous maintenance of the ICD-9-CM is
 the responsibility of the Federal Government.  However,
 because the ICD-9-CM represents the best in contemporary
 thinking of clinicians, nosologists, epidemiologists, and
 statisticians from both public and private sectors, no
 future modifications will be considered without extensive
 advice from the appropriate representatives of all major

 All official authorized addenda through October 1, 1988,
 have been included in this third edition.
 In February 1977, a Steering Committee was convened by the
 National Center for Health Statistics to provide advice and
 counsel to the development of a clinical modification of
 the ICD-9.  The organizations represented on the Steering
 Committee included:

      American Association of Health Data Systems
      American Hospital Association
      American Medical Record Association
      Association for Health Records
      Council on Clinical Classifications
      Health Care Financing Administration,
        Department of Health and Human Services
      WHO Center for Classification of Diseases for North
        America, sponsored by the National Center for Health
        Statistics, Department of Health and Human Services

 The Council on Clinical Classifications is sponsored by:

      American Academy of Pediatrics
      American College of Obstetricians and Gynecologists
      American College of Physicians
      American College of Surgeons
      American Psychiatric Association
      Commission on Professional and Hospital Activities

 The Steering Committee met periodically in 1977.  Clinical
 guidance and technical input were provided by Task Forces
 on Classification from the Council on Clinical
 Classification's sponsoring organizations.

 ICD-9-CM is a clinical modification of the World Health
 Organization's International Classification of Diseases,
 9th Revision (ICD-9).  The term "clinical" is used to
 emphasize the modification's intent:  to serve as a useful
 tool in the area of classification of morbidity data for
 indexing of medical records, medical care review, and
 ambulatory and other medical care programs, as well as for
 basic health statistics.  To describe the clinical picture
 of the patient, the codes must be more precise than those
 needed only for statistical groupings and trend analysis.

 The concept of extending the International Classification
 of Diseases for use in hospital indexing was originally
 developed in response to a need for a more efficient basis
 for storage and retrieval of diagnostic data.  In 1950, the
 U.S. Public Health Service and the Veterans Administration
 began independent tests of the International Classification
 of Diseases for hospital indexing purposes.  In the
 following year, the Columbia Presbyterian Medical Center in
 New York City adopted the International Classification of
 Diseases, 6th Revision, with some modifications for use in
 its medical record department.  A few years later, the
 Commission on Professional and Hospital Activities adopted
 the International Classification of Diseases with similar
 modifications for use in hospitals participating in the
 Professional Activity Study.

 The problem of adapting ICD for indexing hospital records
 was taken up by the U.S. National Committee on Vital and
 Health Statistics through its subcomittee on hospital
 statistics.  The subcommittee reviewed the modifications
 made by the various users of ICD and proposed that uniform
 changes be made.  This was done by a small working party.
 In view of the growing interest in the use of the
 International Classification of Diseases for hospital
 indexing, a study was undertaken in 1956 by the American
 Hospital Association and the American Medical Record
 Association (then the American Association of Medical
 Record Librarians) of the relative efficiencies of coding
 systems for diagnostic indexing.  This study indicated that
 the International Classification of Diseases provided a
 suitable and efficient framework for indexing hospital
 records.  The major users of the International
 Classification of Diseases for hospital indexing purposes
 then consolidated their experiences and an adaptation was
 first published in December 1959.  A revision was issued in
 1962 and the first "Classification of Operations and
 Treatments" was included.

 In 1966, the international conference for the revision of
 the International Classification of Diseases noted that
 the 8th revision of ICD has been constructed with hospital
 indexing in mind and considered that the revised
 classification would be suitable, in itself, for hospital
 use in some countries.  However, it was recognized that
 the basic classification might provide inadequate detail
 for diagnostic indexing in other countries.  A group of
 consultants was asked to study the 8th revision of ICD (ICD
 8) for applicability to various users in the United States.
 This group recommended that further detail be provided for
 coding of hospital and morbidity data.  The American
 hospital Association was requested to develop the needed
 adaptation proposals.  This was done by an advisory
 committee (the Advisory Committee to the Central Office on
 ICDA).  In 1968 the United States Public Health Service
 published the product, Eighth Revision International
 Classification of Diseases, Adapted for Use in the United
 States (PHS publication 1693).  This became commonly known
 as ICDA-8, and beginning in 1968 it served as the basis for
 coding diagnostic data for both official morbidity
 statistics in the United States.

 In 1968, the Commission on Professional and Hospital
 Activities (CPHA) of Ann Arbor, Michigan, published the
 Hospital Adaptation of ICDA (H-ICDA) based on both the
 original ICD-8 and ICDA-8.  In 1973, CPHA published a
 revision of H-ICDA, referred to as H-ICDA-2.  Hospitals
 throughout the United States have been divided in their
 usage of these classifications.  Effective January 1979,
 ICD-9-CM provides a single classification intended
 primarily for use in the United States replacing these
 earlier related but somewhat dissimilar classifications.
 General Information
 ICD-9-CM is published as a three-volume set:

      Volume 1     Diseases:  Tabular List
      Volume 2  Diseases:  Alphabetic Index
      Volume 3  Procedures:  Tabular List and Alphabetic

 ICD-9-CM far exceeds its predecessors in the number of
 codes provided.  The disease classification has been
 expanded to include health-related conditions and to
 provide greater specificity at the fifth-digit level of
 detail.  These fifth digits are not optional; they are
 intended for use in recording the information substantiated
 in the clinical record.

 Volume 1 of ICD-9-CM contains five appendices:

      Appendix A     Morphology of Neoplasms
      Appendix B     Glossary of Mental Disorders
      Appendix C     Classification of Drugs by American
                     Hospital Formulary Service List Number and Their ICD-9-CM
      Appendix D     Classification of Industrial Accidents
                     According to Agency
      Appendix E     List of Three-Digit Categories

 These appendices are included as a reference to the user in
 order to provide further information about the patient's
 clinical picture, to further define a diagnostic statement,
 to aid in classifying new drugs, or to reference three-
 digit categories.

 Volume 2 of the ICD-9-CM contains many diagnostic terms
 which do not appear in Volume 1 since the index includes
 most diagnostic terms currently in use.

 Volume 3 of ICD-9-CM also contains increased clinical
 detail over its predecessors, and this is accommodated by
 expansion of the rubrics from three to four digits.
 The Disease Classification
 General Information
 ICD-9-CM is totally compatible with its parent system, ICD-
 9, thus meeting the need for comparability of morbidity and
 mortality statistics at the international level.  A few
 fourth-digit codes were created in existing three-digit
 rubrics only when the necessary detail could not be
 accommodated by the use of a fifth-digit sub-
 classification.  In these few instances (28 three-digit
 categories) the special symbol > > to the left of the code
 indicates that the content of that category differs from
 its ICD-9 counterpart, but even in such cases it is
 possible to recreate the original ICD-9 rubrics through
 appropriate recombination of the ICD-9-CM categories.  To
 ensure that each rubric of ICD-9-CM collapses back to its
 ICD-9 counterpart, several specifications governed the ICD-
 9-CM disease classification.

 Specifications for The Tabular List
 1.  Three-digit rubrics and their contents are unchanged
     from ICD-9.

 2.  The sequence of three-digit rubrics is unchanged from

 3.  Three-digit rubrics are not added to the main body of
     the classification.

 4.  Unsubdivided three-digit rubrics are subdivided where
     necessary to:

      a)  Add clinical detail

      b)  Isolate terms for clinical accuracy

 5.  The modification in ICD-9-CM is accomplished by the
     addition of a fifth digit to existing ICD-9 rubrics, except
     as noted under #7 below.

 6.  Four-digit rubrics are added to subdivided three digit
     codes only when there is no other means of achieving
     desired detail.  These codes, unique to ICD-9-CM (twenty-
     eight three-digit categories), are marked with the symbol >
     > in the Tabular List.

 7.  The optional dual classification in ICD-9 is modified.

      a)  Duplicate rubrics are deleted:

                1)   Four-digit manifestation categories
                     duplicating etiology entries.

                2)   Manifestation inclusion terms
                     duplicating etiology entries.

      b)   Manifestations of diseases are identified, to the
           extent possible, by creating five-digit codes in the
           etiology rubrics.

      c)   When the manifestation of a disease cannot be
           included in the etiology rubrics, provision for its
           identification is made by retaining the ICD-9 rubrics used
           for classifying manifestations of disease.

 8.  The format of ICD-9-CM is revised from that used in

      a)   American spelling of medical terms is used.

      b)   Inclusion terms are indented beneath the titles
           of codes.

      c)   Codes not to be used for primary tabulation of
           disease are printed in italics with the notation, "code
           also underlying disease."

 1.  Format of the Alphabetic Index follows the format of

 2.  Main terms in the Alphabetic Index are printed in bold
     type face.

 3.  When two codes are required to indicate etiology and
     manifestation, the optional manifestation code appears in
     brackets, e.g., diabetic cataract 250.5 +366.41+.
 The Procedure Classification
 General Information
 An important new development occurred with the publication
 of ICD-9; a Classification of Procedures in Medicine.
 Heretofore, procedure classifications had not been a part
 of ICD, but were published with the adaptations to it
 produced in the United States.

 The ICD-9 Classification of Procedures in Medicine is
 published separately from the disease classification in a
 series of supplementary documents called fascicles.  Each
 fascicle contains a classification of modes of therapy,
 surgery, radiology, laboratory, and other diagnostic
 procedures.  The decision to publish each fascicle as a
 unique document was made in order to permit its revision on
 a separate schedule from the disease classification.
 Primary input to Fascicle V, "Surgical Procedures," came
 from the United States whose adaptations of ICD had
 contained a procedure classification since 1962.  This
 experience was invaluable in constructing a classifica-
 tion to permit analysis of health care services in
 hospitals and primary care settings.

 The ICD-9-CM Procedure Classification is a modification of
 WHO's Fascicle V, "Surgical Procedures," and is published
 as Volume 3 of ICD-9-CM.  It contains both a Tabular List
 and an Alphabetic Index.  Greater detail has been added to
 the ICD-9-CM Procedure Classification necessitating
 expansion of the codes from three to four digits.
 Approximately 90% of the rubrics refer to surgical proce-
 dures with the remaining 10% accounting for other
 investigative and therapeutic procedures.

 Specifications for The Procedure Classification
 1.  The ICD-9-CM Procedure Classification is published in
     its own volume containing both a Tabular List and an
     Alphabetic Index.

 2.  The classification is a modification of Fascicle V
     "Surgical Procedures" of the ICD-9 Classification of
     Procedures in Medicine, working from the draft dated
     Geneva, 30 September - 6 October 1975, and labeled WHO/ICD-
     9/Rev. Conf. 75.4.

 3.  All three-digit rubrics in the range 01-86 are
     maintained as they appear in Fascicle V, whenever feasible.

 4.  Nonsurgical procedures are segregated from the surgical
     procedures and confined to the rubrics 87-99, whenever

 5.  Selected detail contained in the remaining fascicles of
     the ICD-9 Classification of Procedures in medicine is
     accommodated where possible.

 6.  The structure of the classification is based on anatomy
     rather than surgical specialty.

 7.  The ICD-9-CM Procedure Classification is numeric only,
     i.e., no alphabetic characters are used.

 8.  The classification is based on a two-digit structure
     with two decimal digits where necessary.

 9.  Compatibility with the ICD-9 Classification of
     Procedures in Medicine was not maintained when a different
     axis was deemed more clinically appropriate.

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