Non-health care spending reduced infant deaths more than previously reported

Key takeaways:

• Adjusted for inflation and regional price differences, additional spending reduced infant mortality by 0.35 deaths per 1,000 live births.
• Using data through 2021, the reduction was 0.51 deaths per 1,000 births.

The association between additional government spending and reduced infant mortality is stronger than originally reported, according to a study published in Pediatrics.

“The infant mortality rate is a leading population health indicator for which the United States ranks poorly compared with other high-income countries, largely because of substantial disparities by race and socioeconomic status,” Shivani J. Sowmyan, MPH, a research and data associate with the Philadelphia Department of Public Health, and colleagues wrote.

Their research reproduced the results of a study published in 2020 that found a decrease of 0.03 deaths per 1,000 live births for every $0.30 increase in environmental spending and a decrease of 0.02 deaths per 1,000 live births for every additional $0.73 per person social spending from 2000 to 2014.

In their updated methodology, Sowmyan and colleagues calculated the overall association between government spending and infant mortality instead of only the interaction with time. They also looked at within-state changes over time and adjusted for inflation and regional price differences. State spending data was from 2000 to 2014, and infant mortality data was from 2002 to 2016.

According to the original data, the average spending per capita over the study period was $9,030, and the average national infant mortality rate (IMR) was 6.56 deaths per 1,000 live births. Sowmyan and colleagues found that per capita spending ranged from $4,580 in Arkansas in 2000 to $25,340 in Washington, D.C., in 2014, and IMRs ranged from 3.5 deaths per 1,000 live births in Vermont in 2016 to 13.7 deaths per 1,000 live births in Washington, D.C., in 2005.

“The District of Columbia had the highest average expenditures per capita and IMR, but also the largest increases in expenditures and reductions in IMR over time, showing the potential for different between versus within-state associations,” Sowmyan and colleagues wrote.

The researchers found a significantly stronger association between total spending and IMR than the original study. For every additional $2.86 in total spending, IMR decreased by 0.35 deaths per 1,000 live births compared with 0.02 deaths per 1,000 live births in the original study.

When looking at within-state spending, the researchers found that every standard deviation increase in total spending was associated with 0.49 fewer deaths per 1,000 live births, whereas an increase in between-state spending was associated with 0.57 more infant deaths per 1,000 live births.

In addition to replicating the original study, the researchers applied their methodology to spending data from 2000 to 2019 and IMR from 2002 to 2021. With the updated data adjusted for inflation, regional price differences and population changes, Sowmyan and colleagues calculated a decrease in IMR of 0.51 deaths per 1,000 live births for every $2.86 in additional per capita spending. For every $0.61 in extra educational spending, IMR decreased by 0.35 deaths per 1,000 live births, and every $0.30 of environmental spending was associated with 0.31 fewer deaths per 1,000 live births. Social spending was not associated with IMR on average, according to Sowmyan and colleagues.

The researchers compared the association between expenditures and IMR among non-Hispanic Black and non-Hispanic white populations and found each $2.86 in total spending reduced IMR by 5.2% and 2.9%, respectively.

“The previous study greatly underreported the actual association between expenditures and IMR,” Sowmyan and colleagues wrote. “This updated replication analysis with various improvements to causal inference and measurement revealed stronger associations between state and local government expenditures and IMR reductions that may be increasing over time. Coupled with a recent national IMR increase, these findings underscore the significance of continued public investments to improve overall infant health outcomes.”