In a landmark study, scientists from the Cancer Prevention Institute of California (CPIC), the nation’s premier organization dedicated to preventing cancer and to reducing its burden where it cannot yet be prevented, have discovered a startling 19.6-year gap in life expectancy between poor black men and affluent Asian women.
According to the research, Asian females with the highest socioeconomic status had a life expectancy of 84.9 years, whereas the life expectancy for African-American males of the lowest socioeconomic status was 65.3 years.
These results come from a first-of-its-kind, block-by-block analysis of the population of California, a project originally designed to look at cancer survival rates in the state, and reveal differences significantly larger than any previous study based on U.S. Census data.
“By looking at both race and socioeconomic status, and drilling down to the neighborhood level for the latter we were able to uncover this sizeable life expectancy disparity between specific categories of individuals based on their neighborhood socioeconomic conditions,” said CPIC Research Scientist Christina Clarke, Ph.D.
By looking at age-specific gaps in mortality, the study confirmed stark differences for younger populations, especially African-American men living in poorer neighborhoods, but showed that the bulk of the gap in life expectancy was actually due to differences in risk among persons aged 45 and up. Clarke explained, “The most important contributor to life expectancy gaps between the most and least advantaged populations was not violence in young people but rather chronic disease in older people, including treatable conditions like heart disease and diabetes.”
The study found that life expectancy was greatest for Asians/Pacific Islanders, intermediate for Hispanics and whites, and lowest among African Americans. The influence of neighborhood socioeconomic status on life expectancy was most pronounced among African-American and white women and men, and Asian/Pacific Islander men.
“Life expectancy is among the most basic indicators of a population’s well being. We found that poverty or affluence alone didn’t explain the wide differences seen by race in today’s California,” Clarke said. “Our findings show clearly that race matters beyond its association with poverty, which raises even more questions as to why.”
CPIC scientists examined neighborhood-level socioeconomic status, race/ethnicity, sex and age for more than 689,000 deaths among California residents during 1999-2001. The researchers defined six mutually exclusive racial/ethnic groups for analysis: Hispanic, Asian/Pacific Islander, African American, white, Native American, and other/unknown. Socioeconomic status was defined based on education level, proportion with a working-class job, proportion unemployed, median household income, proportion below 200% of poverty line, median rent, and median home value.
“We uncovered these differences while studying cancer survival rates among these groups. The findings were disturbing enough that we pressed to publish them, even though they were outside our immediate focus,” Clarke said.
Summary of Findings
– Race/ethnicity and neighborhood socioeconomic status had substantial and independent influences on life expectancy, underscoring the importance of monitoring health outcomes simultaneously by these factors.
– Overall life expectancy of females was greater than males across socioeconomic status by 4.8 years; the difference was largest in lower socioeconomic status by 5.9 years and smallest in the highest socioeconomic status groups by 3.3 years
– The relevance of neighborhood socioeconomic status on life expectancy varies strikingly by race/ethnicity.
– Life expectancy of African-American and white females of the lowest socioeconomic classification was about six to seven years less than among females of the highest classification. Similar patterns were observed among males.
The findings from the new CPIC study are published in the May issue of the international journal, Social Science & Medicine.
Clarke CA, Miller T, Chang ET, Yin D, Cockburn M, Gomez SL. Racial and social class gradients in life expectancy in contemporary California. Soc Sci Med. 2010 May;70(9):1373-80. Epub 2010 Feb 12.