Autism Tied to 14-Year Gap in Life Expectancy

The life expectancy of people with autism spectrum disorder was 14 years shorter than that of other Americans, Medicaid data showed.

Life expectancy at birth for Medicaid beneficiaries with autism was 64.9 years — 5.6 years less than the overall Medicaid beneficiary population and 13.8 years less than the U.S. general population, reported Guohua Li, MD, DrPH, of the Columbia University Mailman School of Public Health in New York City, and co-authors.

Medicaid beneficiaries with autism had a significantly higher mortality risk than the overall Medicaid population with an age- and sex-adjusted standardized mortality ratio (SMR) of 1.44 (95% CI 1.41-1.46), Li and colleagues reported in a JAMA Network Open research letter.

This excess mortality was present in most categories of diseases and health problems, the researchers pointed out. It was most pronounced with influenza (SMR 10.55), malnutrition (SMR 7.56), pneumonitis due to solids and liquids (SMR 6.92), non-transportation accidents and their sequelae (SMR 4.48), accidental drowning and submersion (SMR 3.26), and pneumonia (SMR 3.06).

“Elevated mortality risk in people with autism spectrum disorder has been reported since the late 1980s, but life expectancy for the autistic population remained unknown because of inadequate data on age-specific death rates,” Li said in a statement.

“The good news is that much of the excess mortality among people with autism spectrum disorder is avoidable through improved social support, primary care, and home- and community-based services,” he added.

Autism research has focused historically on biology, genetic markers, environmental risk factors, diagnosis, and treatments, with less attention to long-term health outcomes, Li and co-authors noted.

“Mortality data are crucial for understanding the long-term prognosis and natural history of autism spectrum disorder,” the researchers wrote. “Although systematic reviews indicate that the overall mortality rate for people with autism spectrum disorder is two to three times the rate of the general population, life expectancy disparity in the autistic population has not been examined because of insufficient age-specific mortality data.”

In their study, Li and colleagues analyzed data from the Transformed Medicaid Statistical Information System, which collects records from Medicaid and the Children’s Health Insurance Program (CHIP). The information included mortality data linked to the National Death Index for beneficiaries in all 50 states and the District of Columbia from 2000 through 2020.

The researchers calculated life expectancies for Medicaid beneficiaries with autism and for the overall Medicaid beneficiary population using U.S. life tables. To identify causes of excess mortality associated with autism, they derived age- and sex-standardized SMRs using the 2010 Medicaid beneficiary population as the standard population.

Over the 21-year study period, 2,048,046 people with autism were enrolled in Medicaid. Most (76.1%) were male. Nearly half (48.5%) were white, 16.7% were Hispanic, 14.6% were Black, and 20.2% were part of other race and ethnicity groups.

Life expectancy for Medicaid beneficiaries with autism varied little by sex or by race and ethnicity. Compared with the general population, autistic women had a greater deficit in life expectancy than autistic men.

Between 2000 to 2004 and 2015 to 2019, life expectancy for Medicaid beneficiaries with autism increased by 1.7 years, but disparities compared with both the Medicaid population and the U.S. general population persisted. In 2020 — the first year of the COVID-19 pandemic — life expectancy declined across all three groups, with the largest drop occurring in people with autism.

The study had several limitations, the researchers acknowledged. Medicaid beneficiaries with autism were likely to have lower socioeconomic status and more severe symptoms than autistic individuals not enrolled in Medicaid. The group included a higher proportion of children, young adults, and males than the general population.

“Despite these limitations, our findings have important implications for developing targeted interventions to reduce preventable excess mortality among people with autism spectrum disorder,” Li and colleagues wrote.