Although nosology (coding classification) systems have been in existence since 1837, coding as a profession did not develop until the government and institutions like hospitals began to collect data about mortality and morbidity in the 1960s. U.S. Hospitals began experimenting with the WHO publication, the International Classification of Causes of Death in 1948. In 1962, the US Public Health Service published the International Classification of Diseases , Adapted for Indexing Hospital Records by Diseases and Operations (ICDA). Finally, in 1968, the ICD-8, the ancestor of ICD-9-CM, served as the basis for coding diagnostic data for official morbidity and mortality statistics in the US. This was also used by hospitals for indexing diagnoses and procedures for patients.
For the most part, coders were individuals who were viewed as clerical workers in the medical record department in the basement of the hospital just next to the morgue. The job of coding was one that hospital administrators tolerated because the statistical reporting was required by law. At first, this was on the federal level, then most states adopted laws requiring additional reporting. And, although all providers would eventually be affected by the coding of morbidity and mortality data, hospitals were the pioneers of this movement. They were some of the largest employers and by far the largest providers of health care in every state. Their size, ability to provide charitable care, and non-profit status made them a prime target for complying with ever-increasing reporting requirements. Little did they know how significantly this would change in the future.
The history of coding also bespeaks many different coding and classification systems. Although the ICD systems were by far the most popularly used world-wide, there are several others that deserve mention here. Interestingly, some of these sprout up again during our discussion of the future of coding.
Classification Systems vs. Nomenclatures
The health care field has both classification systems and nomenclatures. Because both play a role in the history as well as into the future, it is important to understand the distinction between the two. Classification systems, which are the systems historically and currently used in the Coding Profession, group related diseases for statistical reporting. Medical classification systems arrange diseases in groups for reporting purposes. On the other hand, a Nomenclature is a system of preferred terminology for naming disease processes. Edna Huffman in her book Health Information Management, published by the Physician’s Record Company details three basic rules that every effective classification system should follow. They are:
- The set of categories should be derived from a single classification principle, such as an anatomic site, etiology, or medical specialty.
- The set of categories should be exhaustive, permitting every possible diagnostic or operative term to be placed within a category of the classification system. In other words, there is a place for everything.
- The categories within the classification system should be mutually exclusive, so it is not possible to place a given diagnostic or treatment term within more than one category of the system. Thus, everything has a place in the system. Huffman, p. 322
