The study was renewed in 1998 to perform a 15 to 24 year mortality follow-up of the cohort. Time dependencies in the ethnic mortality ratio were examined as well as other covariates such as biochemical parameters, hemodynamic variables, and anthropometric variables such as socioeconomic status, health care access and utilization and migrant status. A sample of 200 Mexican-American and 200 non-Hispanic white death certificates were verified by medical record review. The purpose of the review was to determine whether Mexican Americans, deemed to have died of cardiovascular causes based on medical record review, were more or less likely to have cardiovascular codes (ICDA 390-459) listed on their death certificates than non-Hispanic whites deemed to have died of these causes. The review aided in the interpretation of data relating to possible ethnic differences in cause-specific mortality based on death certificate coding.