Death Certificate data constitute an available, comprehensive, relatively uniform and generally reliable source of information to describe mortality trends in the population. Central to the process of calculating mortality rates and determining leading causes of death is the correct coding of the underlying cause of death. The underlying cause of death, which is the last listed cause in Box 107 of the Death Certificate, is defined as the disease, abnormality, or injury that led to death. It must have an etiologic or pathologic relationship to the intervening and immediate causes of death listed above it, and it must have initiated the lethal chain of events, no matter how long the time interval.
Beginning on January 1, 2000, the County of Orange Health Care Agency, Birth and Death Registration Unit began coding the underlying cause of death on Death Certificates using the International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10). The Tenth Revision differs from the Ninth Revision (ICD-9) in a number of respects although the overall content is similar. Changes have been made in the coding rules for mortality to improve the usefulness of the mortality statistics by giving preference to certain categories and by systematically selecting a single cause of death from a reported sequence of conditions. In order for the coding rules to be applied appropriately, the physician certifying the death and its causes must complete the appropriate sections of the Death Certificate correctly.
To better aid the physician in completing the causes/conditions of death sections on a Death Certificate, the following rules are provided (refer to graphic below):
Up to 4 causes of death can be listed in Box 107 (only 1 cause can be entered on each line). Causes listed in lines A, B, C, and D in Box 107 should be in chronological and pathological order such that the most immediate cause of death is listed in A, any cause listed in B led to the cause in A and preceded it, any cause listed in C led to B and preceded it, and any cause listed in D led to the cause in C and preceded it.
Time intervals listed in lines A, B, C, and D in Box 107 must be in chronological order with the most recent event or condition first.
Box 112 should be reserved for conditions contributing to death but not an underlying cause or one of the causes in the chain of events that led to death.
If an operation is specified in Box 107 or Box 112, then it must also be listed in Box 113.
If a biopsy is specified in Box 107 or Box 112, then "Yes" must also be checked in Box 109.
If no autopsy was performed ("No" checked in Box 110), then either "No" should be checked in Box 111 or Box 111 should be left blank.
A Death Certificate completed in accordance with the rules above will reduce the amount of time spent by the physician, mortuary and registration staff in correcting errors. Additionally, a correct certificate will eliminate the need to file an amendment to the Death Certificate at a later date. Should you have further questions regarding the Death Certificate registration process, please telephone the Birth and Death Registration Unit at (714) 480-6700.