Unsecured debt in early adulthood and premature mortality in adults in the USA: a longitudinal analysis of prospective national cohort data.

BACKGROUND: Premature mortality rates are higher in the USA than other peer nations. Few studies have assessed the association between cumulative unsecured debt and subsequent premature mortality. The aim of this study was to investigate the association between cumulatively accrued unsecured debt over 20 years of early adulthood and subsequent premature mortality in midlife (age 41-62 years). METHODS: For this longitudinal analysis, we used data from 6954 participants included in the US National Longitudinal Survey of Youth 1979. Participants were followed up from 1985 to 2004 to assess debt trajectory, and from 2004 to 2018 to assess premature mortality. A group-based trajectory model was used to classify four groups of unsecured debt trajectories: no debt, constant low debt, constant medium debt, and increasing debt. Multivariable adjusted Cox proportional hazards models were used to assess associations between debt trajectory and mortality. FINDINGS: Of the 6954 participants included in our analysis, 5670 (81·5%) individuals had constant low debt, 712 (10·2 %) had constant medium debt, 148 (2·1%) had increasing debt, and 424 (6·1%) had no debt. In adjusted models, the risk of mortality was 89% higher in the increasing debt group than the constant low debt group (hazard ratio 1·89 [95% CI 1·14-3·12]). In unadjusted models, individuals with no debt had a numerically higher risk of premature mortality compared with those with constant low debt; however, this difference was not statistically significant. INTERPRETATION: Cumulative increasing unsecured debt in early adulthood was associated with increased risk of premature mortality in midlife. Interventions and policies targeting unsecured debt might reduce premature mortality. FUNDING: National Institute of Health National Institute on Aging.