Differential Employment Quality and Educational Inequities in Mental Health: A Causal Mediation Analysis

Background: In the United States, inequities in mental distress between those more and less educated have widened over recent years. Employment quality, a multidimensional construct reflecting the relational and contractual features of employer-employee relationships, may mediate this inequity throughout adulthood, yet no study has examined the extent of this mediation in the United States, or how it varies across racialized and gendered populations. Methods: Using the information on working-age adults from the 2001 to 2019 Panel Study of Income Dynamics, we construct a composite measure of employment quality via principal component analysis. Using this measure and the parametric mediational g-formula, we then estimate randomized interventional analogs for natural direct and indirect effects of low baseline educational attainment (≤high school: no/yes) on the end-of-follow-up prevalence of moderate mental distress (Kessler-6 Score ≥5: no/yes) overall and within subgroups by race and gender. Results: We estimate that low educational attainment would result in a 5.3% greater absolute prevalence of moderate mental distress at the end of follow-up (randomized total effect: 5.3%, 95% CI = 2.2%, 8.4%), with approximately 32% of this effect mediated by differences in employment quality (indirect effect: 1.7%, 95% CI = 1.0%, 2.5%). The results of subgroup analyses across race and gender are consistent with the hypothesis of mediation by employment quality, though not when selecting on full employment (indirect effect: 0.6%, 95% CI = -1.0%, 2.6%). Conclusions: We estimate that approximately one-third of US educational inequities in mental distress may be mediated by differences in employment quality.