Ascertainment of Hispanic ethnicity on California death certificates: implications for the explanation of the Hispanic mortality advantage.

Objectives: We determined the size and correlates of underascertainment of Hispanic ethnicity on California death certificates.

Methods: We used 1999 to 2000 vital registration data. We compared Hispanic ethnicity reported on the death certificate to Hispanic ethnicity derived from birthplace for the foreign-born and an algorithm that used first and last name and percentage of Hispanics in the county of residence for the US-born. We validated death certificate nativity by comparing data with that in linked Social Security Administration records.

Results: Ethnicity and birthplace information was concordant for foreign-born Hispanics, who have mortality rates that are 25% to 30% lower than those of non-Hispanic Whites. Death certificates likely underascertain deaths of US-born Hispanics, particularly at older ages, for persons with more education, and in census tracts with lower percentages of Hispanics. Conservative correction for under-ascertainment eliminates the Hispanic mortality advantage for US-born men.

Conclusions: Hispanic ethnicity is accurately ascertained on the California death certificate for immigrants. Immigrant Hispanics have lower age-adjusted mortality rates than do non-Hispanic Whites. For US-born Hispanics, the mortality advantage compared with non-Hispanic Whites is smaller and may be explained by underreporting of Hispanic ethnicity on the death certificate.