Study Probes Links Between Wealth and Health

Physician's First Watch David G. Fairchild, MD, MPH, Editor-in-Chief In This Issue: April 11, 2016

By Kelly Young

Edited by Susan Sadoughi, MD, and André Sofair, MD, MPH

A new JAMA study provides a comprehensive look at income and life expectancy in the U.S.

Using federal income tax and Social Security data from 1999 to 2014, researchers estimated mortality rates and calculated period life expectancy based on participants' taxable household income at age 40.

Based on 1.4 billion person-years of data, researchers concluded:

• Life expectancy increased continuously with household income. Compared with the bottom 1% of income distribution, men in the top 1% lived nearly 15 years longer, while women lived 10 years longer, a gap equivalent to a lifetime of smoking.
• The discrepancy in life expectancy increased from 2001 to 2014 — people in the top 5% of income increased their life expectancy by as much as 3 years, while the bottom 5% saw little change.
• Looking at different metropolitan areas, there was little variation across the top income percentiles, but substantial variation in life expectancy at the lower incomes. Among participants in the lowest 5% of income across four cities, average life expectancy varied by 6 years.
• Most of the variation in life expectancies observed across geographic areas was tied to differences in health behaviors, not healthcare access or other forces.

Editorialists remind clinicians to consider patients' socioeconomic circumstances: "Amid the excitement over personalized medicine, the fact remains that a patient's zip code may be more useful for targeting therapy than his or her genotype."