Rules for Code Assignment

Simply defining code categories does not ensure data consistency. Both technical and non-technical elements must follow rules for code category assignment. For example, how exactly does an abstractor select among multiple references to morphology in a record? When does the first course of therapy begin and end? Where does a transient live? The need for uniform rules for code assignment is well recognized by registries and standard setters, and more progress in this area is likely to be achieved over the next several years.