Reconciling heart disease mortality and ICD codes.

This study uses 61 years of death certificates for Bexar County, Texas, uniformly coded under ICD 9, to describe the transition in heart disease mortality from 1935-1995. We find that life expectancy for persons dying with heart diseases increased throughout this period, with clear differences in rates of increase for males and females, associated with acute ischemic heart disease. Our data point to an epidemic of AIHD in the 1950s and 1960s, which is now abating. Findings are less clear for chronic ischemic heart disease, while other major heart diseases cannot be traced with any confidence owing to changes over time in the emphasis accorded particular causes. Our findings suggest caution with respect to the socioeconomic analysis of heart disease mortality data, particularly where the instability of the coding conventions has been most acute.