Alabama law requires the physician in charge of the care of the patient for the illness or condition that resulted in death to complete the medical certification section on the death certificate. The physician is requested to state the diseases or conditions that caused the death and other significant conditions contributing to death. If a death occurs with no physician in charge of the care, the county coroner or in a few counties, the medical examiner, is responsible for determining the cause of death.
CLASSIFICATION. For tabulation purposes, causes of death are coded according to the International Classification of Diseases1 (ICD) which provides the essential ground rules for the coding and classification of cause-of-death data. The ICD was developed collaboratively between the World Health Organization (WHO) and ten international centers, one of which is housed at the National Center for Health Statistics (NCHS). The purpose of the ICD is to promote international comparability in the collection, classification, processing and presentation of health statistics. The United States is required to use the ICD under an agreement with WHO that has the force of an international treaty.
The ICD has been revised approximately once every 10 years to stay abreast with advances in medical science and to ensure the international comparability of health statistics. The tenth and most recent revision, known as the ICD-10, was first used to classify deaths that occurred on January 1, 1999 and after. The previous version, the ICD-9, was used from 1979 through 1998.
The ICD-10 is much more detailed with about 8,000 possible categories for cause of death compared with 4,000 categories in the previous version. For the first time, the ICD-10 uses alphanumeric codes. In the tenth revision of the ICD, cause of death titles have been changed and conditions have been regrouped. Some coding rules have also been changed. In addition, ICD-10 tabulation lists used in publications have also changed, so mortality Death. data prepared under different revisions of the ICD may not be comparable (see comparability ratios).
Besides being a classification system for the cause of death, the ICD includes coding rules. These rules identify the single condition on the death certificate considered most informative from a public health point of view, called the underlying cause of death. The underlying cause is the disease or injury initiating the sequence of events that leads directly to death or the circumstances of the accident or violence that produced the fatal injury.
Cause of death data in this website were coded according to procedures established by NCHS2. Starting with death records for 1999, cause of death data were processed through computer software programs from NCHS which allow Center for Health Statistics (CHS) staff to enter the literal information provided by the physician or coroner in the medical certification section of the death certificate. The software programs are written to apply WHO rules to select the underlying cause of death from all the conditions given on the death certificate. Tables in this website contain the underlying cause of death as determined through these procedures.
TABULATION LISTS AND CAUSE OF DEATH RANKINGS. For dissemination and presentation of data, NCHS developed several tabulation lists which group causes of death codes into categories that are of public health interest and medical importance. The lists have increasing levels of detail or are for specific categories of death and are published in Part 9 of the NCHS Instruction Manual Series.3 Certain groups of causes on these lists are used for ranking causes of death to determine the leading causes of death. Starting with 1999 data, the list most widely used to identify and rank the leading causes of death in the United States is the ICD-10 List of 113 Selected Causes of Death. This list replaces the ICD-9 List of 72 Selected Causes of Death used from 1979 through 1998. For areas smaller than the state or nation, a condensed list of selected causes was developed to present cause of death data in Alabama.
COMPARISON OF CAUSE OF DEATH DATA. Changes in moving to a new revision of the ICD can cause major discontinuities in trend data for certain causes of death. To understand the changes in mortality Death. rates that are simply due to the new ICD revision, NCHS double codes a large sample of deaths under each revision to develop comparability ratios. This is simply the ratio of deaths coded under the new revision (ICD-10) divided by the number under the old revision (ICD-9) for a particular cause of death. These ratios are given in Robert Anderson, et. al., Comparability of Cause of Death between ICD-9 and ICD-10: Preliminary Estimates, Hyattsville, MD, National Vital Statistics Reports, Volume 49, Number 2, May 18, 2001. Comparability ratios can be applied to specific cause of death groups that were coded under ICD-9 to see how many deaths in that specific group would result if those same deaths had been coded under the new ICD-10. Application of the comparability ratios is crucial in time trend analyses. For additional information on comparability ratios, see the NCHS web site at www.cdc.gov/nchs.
1World Health Organization. "International Statistical Classification of Diseases and Related Health Problems, Tenth Revision." Geneva: World Health Organization, 1992.
2National Center for Health Statistics. "NCHS Instruction Manual, Part 2a, Vital Statistics, Instructions for Classifying the Underlying Cause of Death." Hyattsville, Maryland: Public Health Service, published annually.
3National Center for Health Statistics, Centers for Disease Control and Prevention. "Instruction Manual Part 9, ICD-10 Cause-of-Death Lists for Tabulation Mortality Death. Statistics, Effective 1999." Hyattsville, Maryland: October, 1997.