Coding causes of death to statistical categories
Mortality coding using the ICD-10
Mortality coding involves two components – the correct assignment of ICD codes to the conditions reported on death certificates of cause of death (COD), and the correct application of mortality coding rules when selecting the underlying cause of death (UCOD). The ICD provides rules for selecting the COD that is most relevant from a health perspective. This is the disease or injury that initiated the sequence of events that led directly to death. In ICD terminology, this is the ‘underlying’ cause of death.
Although the immediate COD or mode of dying will have been of interest to a clinician trying to avert the death, this does not generate the information needed for health decision making, because it says nothing about what led to the death. Moreover, because many deaths are associated with multiple medical conditions – all of which may have contributed to the death – it is essential to identify, among these, the underlying cause in the sequence leading to death; with other causes listed as being contributory rather than causative.
A thorough knowledge and clear understanding of the purpose and structure of the ICD is vital for the correct coding and interpretation of COD information by coders and statisticians. Applying ICD principles and correctly following ICD selection and modification rules are vitally important in accurately identifying the main causes of death in populations. Without the coding of death records and subsequent compiling of statistics, countries will lack reliable data on their particular COD patterns and will have little evidence on which to base health planning and programs.