Life Expectancy

Overall, people living in the United States are living longer, healthier lives. However, the number of years that a person can expect to live varies across demographic groups and geography. In fact, the differences in life expectancy across U.S. counties have broadened over the last several decades.[1] In this case, the impact of geography on life expectancy is reflected in a larger underlying set of causes. People who live near each other predominantly have similar incomes, health care access, food access, environmental exposure, and social norms that can influence things like smoking, drinking, substance abuse, exercise, and more.[3],[4],[5],[6] County action can influence many of these factors, including environmental exposure, food and health care access, and safety nets that can reduce the stress and other health impacts of having a low or precarious income.
Life expectancy is increasingly correlated with income: the gap between life expectancy in the richest and poorest census tracts in California increased from an 11.5 year difference in 2019 to a 14.7 year difference in 2020, and to 15.5 years in 2021.[7] Further, there are differences in mortality rates when evaluated by race and ethnicity minority groups. In California in 2021, life expectancy in years for non-Hispanic Asians was 83.5, non-Hispanic Whites was 78.7, Hispanics was 76.8, and non-Hispanic Blacks was 71.0. Nationwide in 2021, life expectancy in years for non-Hispanic Asians was 83.5, 77.7 for Hispanics, 76.4 for non-Hispanic Whites, and 70.8 for non-Hispanic Blacks.[8]
This report reflects life expectancy at birth. Life expectancy at birth represents the average number of years a person born that year would live if they were to experience throughout life the age-specific death rates prevailing during that year. This measure is useful for understanding the geographic variation within and between counties and then observing the effects of population-wide events and interventions. However, this method does leave out some information. For example, life expectancy can also be calculated by cohort, estimating the life expectancy for all people of a certain birth year.[9] The cohort method is more useful for an individual trying to assess their own life expectancy. Period-level life expectancy is of interest for showing geographic variation within the county and observing the impact of interventions that are not isolated to cohorts. However, when interpreting the numbers in this report, it is still important to remember that cohort factors can influence life expectancy across the county. For example, during the COVID-19 pandemic, life expectancy declined in 2020 and again in 2021, at not just the county level but the state and federal levels as well.[10] Further, because COVID-19 impacts people differently across the life course, it may have lowered the life expectancy for people born in 1950 more than those born in 1990.
To estimate life expectancy in different areas throughout the county, the Public Health Services Community Health Statistics Unit (CHSU) in the County of San Diego’s Health and Human Services Agency uses SANDAG estimates of population in its denominator.[11] In order to make annual life expectancy estimates of smaller geographic areas in San Diego County a more robust population estimate is required. The report relied on population projections made using 2010 census data because 2020 census data were not available at the time. CHSU reports life expectancy by sex and by the racial categories of Asian, Black, Hispanic, and White. Unfortunately, these data are not disaggregated by other important features like disability status, immigrant status, or a more comprehensive and granular view of race.
In 2021 in San Diego County, the overall life expectancy of San Diego County residents was 80.6 years, meaning that children born in 2021 are expected to live 80.6 years on average. In 2021, life expectancy was higher in San Diego County compared to California (78.4 years) and the U.S. (76.1 years).[12],[13] Life expectancy was lower for Hispanics and Blacks compared to the county overall (Figure 1), and lower for males compared to females (Figure 2). In 2021, subregional areas of San Diego County had life expectancies ranging from 73.3 years in Chula Vista to 88.9 in University, which includes communities near the University City neighborhood within the City of San Diego (Figure 3).

Data Information
Data Sources: California Department of Public Health, Center for Health Statistics, Office of Health Information and Research, Vital Records Business Intelligence System (VRBIS). SANDAG Population Estimates, 2021 (vintage: 09/2022). Prepared by County of San Diego, Health and Human Services Agency, Public Health Services, Community Health Statistics Unit, 2022.
Figure 3 Footnote:
  • Unavailable data are censored due to variation in population size.
References 
  1. ScienceDirect. (2020). Explaining the spatial variation in American life expectancy. Retrieved September 9, 2022, from https://www.sciencedirect.com/science/article/abs/pii/S0277953619307543
  2. McPherson, M., Smith-Lovin, L., & Cook, J. M. (2001). Birds of a feather: Homophily in social networks. Annual Review of Sociology, 27, 415–444.
  3. Reardon, S. F., & Bischoff, K. (2011). Income inequality and income segregation. American Journal of Sociology, 116(4), 1092–1153. https://doi.org/10.1086/657114  
  4. Bezin, E., & Moizeau, F. (2017). Cultural dynamics, social mobility and urban segregation. Journal of Urban Economics, 99, 173–187. https://doi.org/10.1016/j.jue.2017.02.004  
  5. Smith, K. P., & Christakis, N. A. (2008). Social networks and health. Annual Review of Sociology, 34, 405-429.
  6. Schwandt, H., Currie, J., von Wachter, T., Kowarski, J., Chapman, D., & Woolf, S. H. (2022). Changes in the relationship between income and life expectancy before and during the COVID-19 pandemic, California, 2015-2021. JAMA, 328(4), 360–366. https://doi.org/10.1001/jama.2022.10952
  7. Arias, E., Betzaida, T-V., Kochanek, K.D., & Ahmad, F.B. (2022). Provisional Life Expectancy Estimate for 2021. National Vital Statistics System, Vital Statistics Rapid Release Report No. 23. National Center for Health Statistics. Retrieved from, Vital Statistics Rapid Release,Number 023 (August 2022) (cdc.gov)
  8. Luy, M., Di Giulio, P., Di Lego, V., Lazarevič, P., & Sauerberg, M. (2020). Life expectancy: Frequently used, but hardly understood. Gerontology, 66(1), 95–104. https://doi.org/10.1159/000500955
  9. Schwandt, H., Currie, J., von Wachter, T., Kowarski, J., Chapman, D., & Woolf, S. H. (2022). Changes in the relationship between income and life expectancy before and during the COVID-19 pandemic, California, 2015-2021. JAMA, 328(4), 360–366. https://doi.org/10.1001/jama.2022.10952
  10. Life Expectancy in San Diego County 2010-2021. Retrieved, LifeExpectancyinSanDiegoCounty2010-2021.pdf    
  11. Schwandt, H., Currie, J., von Wachter, T., Kowarski, J., Chapman, D., & Woolf, S. H. (2022). Changes in the relationship between income and life expectancy before and during the COVID-19 pandemic, California, 2015-2021. JAMA, 328(4), 360–366. https://doi.org/10.1001/jama.2022.10952
  12. Life Expectancy in the U.S. Dropped for Second Year in a Row in 2021. National Center for Health Statistics (2022). Life Expectancy in theU.S. Dropped for the Second Year in a Row in 2021 (cdc.gov)
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Updated January 17, 2024