"Mortality studies of ethnic and religious subgroups within a nation are of interest as they provide indicators of health differentials that may result from differences in life style and risk-factor exposures.  The mortality experience of North American Jews has been documented over many years and is of particular interest because of the unusual pattern that has been observed, a crossover from relatively low rates at younger ages to relatively high rates at older ages.  This study examines mortality in 1979-81 among more than 100,000 Medicare enrollees who held 22 surnames common among American Jews.  The findings substantiate those of a recent mortality study of a Canadian Jewish population which indicated more rapid improvement in life expectancy among elderly Jewish than non-Jewish males, and a lessening of the relative disadvantage of elderly Jewish women."