Life Expectancy

Life Expectancy, by Age

Doctors see frail old people, and sometimes assume they have few remaining days left, and comfort is most important. However at every age we have 8 or more months left, and up to 112 we have over a year of life expectancy left. Those with good minds may want to enjoy that time. With each additional year we live, our life expectancy extends by 9 or 10 months, and with good care and luck we keep living. The data are prepared by the Social Security Administration.
 
CDC has instructions to doctors on filling out death certificates, but there are weaknesses and errors, especially for the minority of patients who die without a recent doctor visit.

An example of under-treating old people is for cancer care, even though most cancer patients are old.

Average Years of Life Remaining, at Each Age, US Population, 2014

Doctors' Inaccurate Predictions of Life Expectancy

Doctors use many versions of the Charlson Comorbidity Index to estimate life expectancy for patients, depending on their age and illnesses (comorbidities). Many versions are little better than chance in predicting life expectancy.

The C statistic is an estimate, from a research project on particular patients, how often an index is more accurate than chance. Values range from 0.50 (no better than chance) to 1.00 (always right). C statistics for different groups of patients are in supplementary tables 1-4 of Yurkovich et al. (2015) Journal of Clinical Epidemiology. v.68(1):3–14. "A systematic review identifies valid comorbidity indices derived from administrative health data." Details of how big the errors are may be found in the original studies, listed by Yurkovich et al.

An older study is Sharabiani et al. (2012 Dec) Medical Care. v.50(12):1109-18. "Systematic review of comorbidity indices for administrative data." . doi: 10.1097/MLR.0b013e31825f64d0 pubmed.gov/22929993

​US Life Expectancy Stopped Improving 

US life expectancy overall, and specifically for people over 65 was improving similarly to other rich countries before the 1980s. It kept improving at a slower rate until around 2011. Since then it has been flat (Bloomberg, and CDC p.116, table 15).

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Life Expectancy by Location

JAMA Internal Medicine identified life expectancy for each US county from 1980 to 2014, with an article discussing it. The counties with highest life expectancy often have high income, and often a lot of outdoor recreation.

Life expectancy is a good summary of health in the area, since it is a summary of death rates at all ages in each county. It is not a prediction for babies born in the county, since their lifetimes will depend on future death rates, not current or past ones.

Associated Press has a map of life expectancy for each US Census tract (smaller than counties) for 2017 from the National Center for Health Statistics, with an article discussing it.

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​US News & World Report has maps and data for each county on many health measures.

CountyHealthRankings.org has detail on each county's health. West Virginia University analyzed it nationally, and found the top-ranked counties have less of the following problems (pages 83-85):

• ​lack of sleep and exercise
• physical and mental distress
• diabetes
• obesity
• Human Immunodeficiency Virus (HIV) and sexually transmitted diseases
• segregation
• air particulates
• smoking
• drunk-driving (but no difference in drinking overall)
• drug and car deaths

• violent crime

Presumably some of these are causes and some are results of overall population health. Some are norms which can persist for a long time.
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Local life expectancy is persistent for at least 34 years, 1980-2014. The lowest counties stayed below average and the highest counties stayed above average.  Average US life expectancy rose 5 years, from 74 to 79, and most of the lowest counties rose a bit more, getting closer to average, which is encouraging. However the most common rise was 4 years, and 71% of counties rose 3, 4 or 5 years, so they mostly stayed close to where they were 34 years before.

Life expectancy is higher in richer countries, and in formerly communist countries, which emphasized access to food and health care (teaching notes).

Life Added by Hospital Treatment

Researchers at Columbia and Yale found that even an extra day of hospital treatment for pneumonia or heart attack saves thousands of lives (Table H). So reducing access to hospital treatment will be deadly.

Table H. Lives Saved by More Hospital Treatment