The individual and combined associations of depression and socioeconomic status with risk of major cardiovascular events: A prospective cohort study

Objective: We aimed to investigate the individual and combined associations of depression and low socioeconomic status (SES) with risk of major cardiovascular events (MCVE), defined as first-ever fatal or non-fatal stroke or myocardial infarction, in a large prospective cohort study.
Methods: We used data from 466,238 UK Biobank participants, aged 40 – 69 years without cardiovascular disease, bipolar disorder or schizophrenia at baseline. We performed Cox proportional hazard models to estimate adjusted hazard ratios (HR) and 95% confidence intervals (CI) for the individual and combined associations of depression and each of educational attainment, area-based deprivation and income with risk of MCVE. We assessed effect modification and explored interaction on the additive and multiplicative scale.
Results: Depression, low education, high area-based deprivation and low income were individually associated with increased risks of MCVE (adjusted HR, 95% CI: 1.28, 1.19 – 1.38; 1.20, 1.14 – 1.27; 1.17, 1.11 – 1.23; and 1.22, 1.16 – 1.29, respectively). Depression was associated with increased risks of MCVE among individuals with high and low SES. Individuals with depression and each of low education, high area-based deprivation and low income were at particularly high risk of MCVE (HR, 95% CI: 1.50, 1.38 – 1.63; 1.63, 1.46 – 1.82; 1.31, 1.23 – 1.40, respectively). There was interaction between depression and area-based deprivation on multiplicative and additive scales but no interaction with education or income.
Conclusion: Depression was associated with increased risks of MCVE among individuals with high and low SES, with particularly high risks among those living in areas of high deprivation.