Life Expectancy

Average years of life expectancy at birth

Source:
U.S. Small-area Life Expectancy Estimates Project (USALEEP). Calculated by the Dashboard Team using data from 2015, 6 year modeled estimate.
698678.9
Dashboard-City Average

Why do we measure life expectancy?

Life expectancy can be used to evaluate the health status of a population and identify groups who are at risk of dying before we would expect.1 Factors such as access to medical care, physical environment, employment opportunities, social inequalities, health behaviors, and preventable health conditions can contribute to reduced life expectancy.1,2 In 2016, the life expectancy at birth for the total population in the U.S. was 78.6 years.3 The top three leading causes of death were heart disease, cancer, and unintentional injuries.3 Life expectancy varies across population subgroups; people with low incomes and certain racial and ethnic groups have lower-than-average life expectancies.1-4 

How do we measure life expectancy?

Life expectancy is the average number of years a person can expect to live, based on the experiences of the group of people who live in that same area.5  

Strengths and Limitations

Strengths of Metric

Limitations of Metric

• The life expectancy metric includes all deaths in a population, thus providing a snapshot of the entire community. 

• The calculations reported here have been tailored to directly address small-area estimation challenges, such as small numbers of deaths, missing age-specific death counts, and small population sizes.6

• It can be difficult to pinpoint what causes differences in life expectancy among communities because many factors contribute to mortality.2 

• Life expectancy estimates do not change significantly from year to year. Therefore, it is not useful  for tracking short-term improvement.

 

Calculation

Life expectancy estimates are calculated by constructing a life table for each census tract. Ages are aggregated into five-year intervals, except the first two groups (aged 0-1 and aged 1-5 years).6 Death rates for the age groups are calculated over the six-year period and applied to a hypothetical birth cohort to estimate the probability of surviving to the next five-year age group.6 The life expectancy estimate is a summary measure based on the number and age of death of the residents in each census tract during the years of 2010-2015.5 

For more information, please refer to the City Health Dashboard Technical Document.

Data Source

Estimates for this metric are from U.S. Small-area Life Expectancy Estimates Project Data. The U.S. Small-area Life Expectancy Estimates Project (USALEEP) is a joint effort of the National Association for Public Health Statistics and Information Systems (NAPHSIS), the Centers for Disease Control and Prevention’s National Center for Health Statistics (NCHS), and the Robert Wood Johnson Foundation (RWJF).

References

  1. Xu J, Murphy SL, Kochanek KD, Bastian BA. Deaths: final data for 2013. National Vital Statistics Reports. 2016;64(2).

  2. Chetty R, Stepner M, Abraham S, et al. The association between income and life expectancy in the United States, 2001-2014. Jama. 2016;315(16):1750-1766.

  3. Kochanek KD, Murphy SL, Xu JQ, Arias E. Mortality in the United States, 2016. Hyattsville, MD: National Center for Health Statistics;2017.

  4. Murray CJL, Kulkarni SC, Michaud C, et al. Eight Americas: Investigating Mortality Disparities across Races, Counties, and Race-Counties in the United States. PLOS Medicine. 2006;3(9):e260.

  5. National Association for Public Health Statistics and Information Systems. USALEEP Neighborhood Life Expectancy Project Message Guide. 2018; http://usaleep.nptoolkit.org/wp-content/uploads/sites/19/2018/05/USALEEP-Message-Guide_Final.pdf. Accessed September 27, 2018.

  6. Arias E, Escobedo LA, Kennedy J, Fu C, Cisewski J. U.S. Small-area Life Expectancy Estimates Project: Methodology and Results Summary. 2018.

Last updated: July 26th, 2023