Does education modify the association between depression and cardiovascular health? (from the National Health and Nutritional Examination Survey, 2013–14 and 2015–16)

Study objective: Depression and education have associations with cardiovascular health. We hypothesized educational attainment would modify the association between depression and cardiovascular health. Design: We used the Patient Health Questionnaire (PHQ), a validated instrument to categorize individuals as having minimal (0-4), moderate (5-9) or severe (≥10) depression. We employed the American Heart Association's Life's Simple 7 (LS7) comprised of known cardiovascular risk factors. In multivariable-adjusted analyses we related PHQ to cardiovascular health measured by LS7. We then evaluated the modification of the association between depression and cardiovascular health by educational attainment. Participants: Individuals age ≥18 years participating in the National Health and Nutrition Examination Survey 2013-214 and 2015-16 cycles. Main outcome measures: LS7, continuous (0-14) and categorized as poor (0-4), intermediate (5-9) or ideal (10-14). Results: In total 8727 individuals (age 48 ± 17 years; 51% female sex; 70% white race; 14% < high school graduate; 32% ≥ college graduate) were included. Among those with mild depression, educational attainment greater than a high school degree or equivalent was significantly more likely to have higher LS7 scores than those without high school graduation. In participants with moderate depression, only those with college education or greater were more likely to have higher LS7 scores (odds ratio [OR] 3.49, 95% confidence interval [CI] 2.01-6.08). In those with severe depression, educational attainment did not modify LS7 scores. Conclusions: Our findings suggest that educational attainment modifies the association between depression and cardiovascular health. This study provides insight on how social factors modify depression, a well-recognized contributor to cardiovascular health.