Adults who experience poverty-level family income-whether sustained or intermittent-over two decades spanning young to mid-adulthood face a significantly higher risk of dying prematurely than those who are never in poverty, according to a new study by Columbia University Mailman School of Public Health researchers. A companion study by the same research team finds that rising unsecured debt-such as credit card debt not tied to an asset-may be one mechanism linking early-life financial hardship to higher mortality risk. Findings from both studies are published in the same issue of The Lancet Public Health.
Both studies used data from the National Longitudinal Survey of Youth 1979 (NLSY79). The poverty study tracked income data from 1985 to 2004, when participants were ages 23 to 42, and followed mortality outcomes through 2019, when participants were ages 53 to 62. Adults who spent more years in poverty had more than twice the rate of premature mortality compared with those who were never in poverty.
"Greater cumulative exposure to poverty across emerging and established adulthood is associated with a greater risk for premature mortality," said Adina Zeki Al Hazzouri, PhD, assistant professor of Epidemiology at Columbia Mailman School and senior author. "By only considering income at a single time point, previous studies may have missed the nuanced and dynamic nature of poverty and the health consequences of even intermittent financial hardship." Their findings highlight the importance of interventions aimed at reducing poverty during key life periods, especially for vulnerable groups, although future research is needed to better understand the impact of support during these stages on long-term health.
In the second study, Zeki Al Hazzouri and colleagues analyzed data from 6,954 NLSY79 participants to assess how trajectories of unsecured debt across 20 years of early adulthood relate to premature mortality in midlife (ages 41-62). They found that individuals whose unsecured debt increased over time had a 89 percent higher risk of death compared with those whose debt remained consistently low.
"This category of debt carries higher interest rates and does not contribute to wealth accumulation. It may be more stressful and burdensome than other types of debt and signal additional resource constraints. So, it is particularly important to study as a social determinant of health," said Zeki Al Hazzouri.
Together, these two studies show that experiences with poverty and strained financial resources are important determinants of health outcomes, including premature mortality. Importantly, the researchers' results draw attention to financial well-being as a dynamic factor that may have varying effects on long-term health across different periods.
An accompanying commentary by Harvard Medical School and CUNY Professors David Himmelstein and Steffie Woolhandler underscores a striking dose-response relationship between years spent in poverty or encumbered by unsecured debt and premature mortality. They suggest the results of both studies may help to explain why poverty in the U.S. appears more damaging to health or why individuals in low wealth quintiles are far less likely to transition to a higher income quartile than in similarly wealthy nations-because insufficient social and medical supports in the U.S. may amplify effects. They call for policies that "prevent and mitigate the consequences of financial burden or otherwise deepen poverty" as a core public health strategy.
Co-authors are Calvin L Colvin, Xuexin Yu, Zihan Chen, Columbia Mailman School of Public Health; Samuel L Swift, University of New Mexico College of Population Health; Sebastian Calonico, University of California, Davis; and Katrina L Kezios, Columbia Mailman School and Boston University School of Public Health.
The research was supported by the National Institute on Aging at the National Institutes of Health (grants AG072681, AG072681-03S1, AG084769 AG084769).
