Coding causes of death to statistical categories
Limited access to resources
One of the most serious limitations is shortage of human resources for coding and lack of other resources, including IT equipment and sufficient copies of the three ICD volumes. Having access to the right tools is vital for good coding. Coders should work from a copy of the three ICD volumes to ensure the proper assignment of codes. However, because the ICD volumes are expensive, many countries rely on too few copies or use photocopied summary sheets.
Many countries now use automated computer programs to help coders select the correct UCOD. The use of automated coding systems minimises the number of subjective decisions that a coder has to make, and helps improve the quality of mortality coding by ensuring that all coders consistently assign the same code to the terms used on death certificates. However, it is essential to note that automated coding systems cannot deal with all cases. Complex cases in which there are multiple comorbidities as well as external causes of death require manual coding.
The Mortality Medical Data System (MMDS) decision tables were originally developed by the Centres for Disease Control and Prevention (CDC) in 1967 to automated the entry, classification, and retrieval of COD information reported on medical certificates of cause of death in the United States. They are used to help determine the correct UCOD and to assign valid COD codes. The decision tables are available to download for free from: http://www.cdc.gov/nchs/nvss/mmds.htm