Aging, migration, and mortality: current status of research on the Hispanic paradox.

OBJECTIVE: We reviewed recent evidence on the apparent Hispanic mortality paradox.
METHODS: Recent studies using vital statistics, national community surveys linked to the National Death Index, Medicare data linked to application records for social security cards maintained in the Social Security Administration NUDIMENT file, and mortality follow-up by regional studies are reviewed critically.
RESULTS: Data based on vital statistics show the greatest mortality advantage compared with non-Hispanic Whites for all Hispanics combined. The advantage is greatest among older people. National Community Surveys linked to the National Death Index show a narrowing of the advantage, and one study suggests that the Mexican Origin mortality advantage can be attributed to selective return migration of less healthy immigrants to Mexico. The Medicare-NUDIMENT data that avoid problems of other data sets also show an advantage in mortality among Hispanic elders, although the advantage is considerably lower than is found using the vital statistics method. DISCUSSION: Although some research has recently begun to question whether indeed all Hispanic groups enjoy a mortality advantage, the majority of the evidence continues to support a mortality advantage at a minimum among Mexican Americans and especially in old age, at least among men, which may provide partial, albeit indirect, support for a selective return migration or "salmon bias" effect. There is a need to further explore the existence of a selective return migration effect with expanded data bases that include more subjects from the various Hispanic origins. To date, the majority of the evidence continues to support the Hispanic paradox at least among people of Mexican origin and calls for additional attention to this interesting and highly important phenomenon.