摘要：Objectives. We tested the data artifact hypothesis regarding the Hispanic mortality advantage by investigating whether and to what degree this advantage is explained by Hispanic origin misclassification on US death certificates. Methods . We used the National Longitudinal Mortality Study, which links Current Population Survey records to death certificates for 1979 through 1998, to estimate the sensitivity, specificity, and net ascertainment of Hispanic ethnicity on death certificates compared with survey classifications. Using national vital statistics mortality data, we estimated Hispanic age-specific and age-adjusted death rates, which were uncorrected and corrected for death certificate misclassification, and produced death rate ratios comparing the Hispanic with the non-Hispanic White population. Results . Hispanic origin reporting on death certificates in the United States is reasonably good. The net ascertainment of Hispanic origin is just 5% higher on survey records than on death certificates. Corrected age-adjusted death rates for Hispanics are lower than those for the non-Hispanic White population by close to 20%. Conclusions . The Hispanic mortality paradox is not explained by an incongruence between ethnic classification in vital registration and population data systems. Mortality rates reported for Hispanics in the United States are lower than those for non-Hispanic Whites. Because the average socioeconomic status of Hispanics is lower than that of non-Hispanic Whites, the relatively low mortality of Hispanics has been called an epidemiologic paradox. 1 The explanation of lower Hispanic mortality remains a matter of investigation. 2 – 5 Palloni and Arias 3 identified 4 groups of explanations: (1) poor data quality (the data artifact hypothesis), (2) selective immigration of healthier persons (the healthy migrant hypothesis), (3) selective return migration of less healthy immigrants (the “salmon-bias” hypothesis), and (4) positive cultural influences on individual health and lifestyle behaviors, family structure, and social networks. Information about Hispanic mortality comes from 2 types of studies. In the first type of study, death counts from the US Vital Statistics System (NVSS) are used as numerators and population counts from the US Census are used as denominators for death rate calculations. In the second type of study, sometimes called passive follow-up studies, records from large survey samples or administrative databases are linked to death certificates. Matched subjects are coded as deceased on the date reported on the death certificate, and unmatched cases are presumed alive. This information is used to calculate mortality rates for the subjects in the sample or administrative database. Both types of studies report lower age- and gender-adjusted mortality rates for Hispanics in the United States than for non-Hispanic Whites. 5 – 7 Each type of study is subject to data problems, which can be grouped into 3 types: ethnic classification errors, record linkage errors, and age misstatement. 3 Ethnic classification errors are inherent in data systems that rely on 2 distinct data sources—NVSS and census—for the estimation of vital rates. Mortality follow-up studies are vulnerable to failures of the algorithm linking the survey or administrative records to death records if the linkage algorithms fail at a differential rate for the 2 groups being compared. Mortality rates calculated in both types of studies are vulnerable to age misstatement. The debate concerning the role of these data problems on the Hispanic paradox has not been resolved. In particular, the question remains whether the lower mortality of Hispanics observed in US vital statistics data results from discrepancies between the assignment of Hispanic origin on the death certificate that supplies the numerator for vital rates and on the census forms that provide the denominator. All evidence confirms that some degree of correction of Hispanic rates for these errors is warranted, although no consensus exists on the size of the errors and the resulting impact on vital rates. 8 – 12 The ethnic identity of the decedent is recorded on the death certificate by the funeral director, who is responsible for completing the demographic portion of the death certificate and registering it with the state vital statistics office. Whether the funeral director consults with the family of the deceased is not ascertained. Ethnic identity is most typically reported on the census form by a respondent living in the household. These identities may not agree because the funeral director will likely have less information about the ethnic ancestry and personal identity of decedents. Before the 1980 US Census, populations of Hispanic origin were identified indirectly by matching surnames of census respondents and decedents to a list of common Spanish surnames in several Southwestern states. 8 , 13 , 14 The 1980 US Census introduced a Hispanic origin item for the first time on all census forms. By 1980, 21 states had introduced a Hispanic origin item to their death certificates. However, Florida, an important Hispanic origin state, did not include a Hispanic origin item on the death certificate until 1989. California was missing responses on the Hispanic origin item for more than 50% of death certificates through 1982. The leading source of data about discrepancies in ethnic classification on the death certificate and population surveys or censuses is the National Longitudinal Mortality Study (NLMS). The NLMS is a database consisting of US Census Bureau data from Current Population Surveys (CPSs) and the 1980 US Census combined with death certificate information to identify mortality status and cause of death. The NLMS has been used in several passive follow-up studies of Hispanic mortality. 6 , 7 The NLMS can also be used to investigate the validity of death certificate ethnic classification by comparing ascertainment of Hispanic ethnicity in survey responses and on the death certificate for linked records. Studies using data from an early release of the NLMS reported a net ascertainment ratio of 1.07 for survey compared with death certificate assignment of Hispanic origin. 9 , 10 This finding suggested a small correction to death rates for Hispanics, which remain lower than those of non-Hispanic Whites after correction. 5 These studies had important limitations, however. The NLMS at this time contained a sample of only 600 linked death certificate records that were classified as Hispanic in survey responses. Estimated ascertainment ratios were imprecise, and subpopulation analysis was not possible. The NLMS at this time included deaths that took place from 1979 through 1985, a period during which only 21 states included a Hispanic origin item on their death certificates. 9 , 10 We tested the data artifact hypothesis as it pertains to ethnic classification across 2 distinct data systems: vital registration and census data. The data artifact hypothesis, as it pertains to ethnic classification, posits that incongruence between ethnic classification in the numerators and denominators of death rates leads to artificially lower death rates for Hispanics than for non-Hispanics, and therefore the appearance of a mortality advantage. We used the latest release of the NLMS to carry out our analysis for deaths that took place in 1979 through 1998. We used the sample of survey records that were matched to death certificate information in the NLMS to assess the sensitivity, specificity, and net ascertainment of Hispanic ethnicity on the death certificate compared with the identification of Hispanic ethnicity by a household respondent. We also investigated differential rates of net ascertainment in relation to sociodemographic and area characteristics, including age, gender, immigrant status, census region, urban or rural status, and residence in a county with a high concentration of Hispanics. We calculated death rates and death rate ratios for the United States by comparing Hispanics and non-Hispanic Whites with correction for death certificate misclassification of Hispanic identity.
