Why separate query pages for CMF 1979-98 and CMF 1999 and later?
The International Classification of Diseases (ICD) is used to classify underlying cause of death. The ICD Ninth Revision is used from 1979-1998, and the ICD Tenth Revision is used since 1999. The classification systems differ significantly. As a result of these changes, the two classification schemes are different enough to make direct comparisons of cause-of-death difficult. NCHS has conducted a comparability study to measure the discontinuities between the Ninth and Tenth Revisions of the ICD for selected causes of death.
