Application of ICD-10-WHO
ICD-10-WHO is a diagnostic classification, i.e. a classification system to make content accessible, e.g. the cause of death certificate: To which category in the classification should the natural language text entries in the certificate be assigned, i.e. by which code(s) are they correctly represented? The assignment of the relevant code is the encoding process.
What needs to be observed?
The most important basic rules are:
- Tabular List ("Systematisches Verzeichnis") and Alphabetical Index ("Alphabetisches Verzeichnis") always have to be used together in order to find the correct code.
- You can only encode what has been sufficiently and accurately documented. (To improve the documentation of causes of death on death certificates, DIMDI in cooperation with the Federal Statistical Office has published an instruction for completing the cause of death certificate.)
The comprehensive Instruction Manual ("Regelwerk") in Volume 2 of ICD-10-WHO contains general rules for the encoding of mortality and morbidity as well as numerous examples.
The categories of the Tabular List often include subclassifications and class attributes, e.g. definitions of diagnoses, inclusions and exclusions as well as coding hints. Such class attributes may also be provided for the higher hierarchy levels, i.e. under sub-group, group and chapter headings; this information needs to be heeded for subordinate codes.
The Alphabetical Index contains an introduction with hints on the best approach to searching for a disease name.
Encoding example: "Wirbelsäulenfraktur" (fracture of the spinal column)
The easiest option is to encode using the Alphabetical Index. It contains more than 75,000 diagnoses in alphabetical order, each associated with the appropriate ICD-10-WHO code. However, the code found in the Alphabetical Index needs to be cross-checked in the Tabular List. First, this is to ensure that the code you have found is in the right context within the Tabular List. Second, the various hierarchical levels of the classification may well contain specific coding notes pertaining to the code, the group of codes or the entire chapter.
How do you encode "Wirbelsäulenfraktur" (spinal fracture)?
- If the search term consists of several components, your first step is to identify the lead term or terms. In our example, the lead terms are "Fraktur" (fracture), "Wirbel" (spine) and "Wirbelsäule" (spinal column).
- Now ascertain whether it is a disease or an injury or a condition associated with Chapters I to XIX or XXI of the Tabular List; in this case, you have to look in Part I of the ICD-10-WHO Alphabetical Index. If it is the external cause of an injury or an event associated with Chapter XX, you have to look in Part II. Poisoning with drugs or chemicals or unwanted effects of drugs are found in Part III. The spinal fracture is an injury and thus has to be looked up in Part I.
- Look in Part I under "Fraktur" (Fracture). Amongst the indented terms (modifiers), you find the entry: "Wirbel" (vertebra) and the code T08. Sometimes, there are cross-references to guide you to the correct entry.
- Looking up this code in the Tabular List, you find a subclassification for the fourth digit according to whether it is a closed ("geschlossen" 0) or an open ("offen" 1) fracture. You also find a reference that a fracture that is not described as closed or open should be classified as a closed fracture. The rule book also tells you, for example, that the fourth digit is separated by a decimal point and that this fourth digit is of no relevance in international reporting, but that it can be important for the encoding in the actual case depending on the problem in question.
- T08.0 is the code you looked for. However, be cautious: There is an exclusion for category T08. that in case of multiple fractures ("Multiple Frakturen...") the correct code is T02.1- and not T08.
- Furthermore, you should make sure that there are no further encoding or exclusion terms under the heading of the higher level group "Verletzungen nicht näher bezeichneter Teile des Rumpfes, der Extremitäten oder anderer Körperregionen" (Injuries to unspecified part of trunk, limb or body region) (T08-T14) and under the chapter heading of "Verletzungen, Vergiftungen und bestimmte andere Folgen äußerer Ursachen" (Injuries to unspecified part of trunk, limb or body region) (S00-T98) that are of relevance to the T08 code. For both, there are exclusion terms that you need to take into account.
- The code you looked for is T08.0 provided you have correctly observed all exclusion terms and other references on all hierarchical levels and that no other code more appropriate to your special case has been mentioned there.