Socioeconomic status and risk of incident venous thromboembolism.

BACKGROUND Although venous thromboembolism (VTE) is a leading cause of morbidity and mortality, and socioeconomic status (SES) affects human health and health behavior, few studies have examined the association between SES and VTE. OBJECTIVES We aimed to investigate the association between SES, assessed individually and in a composite score by levels of education, income, and employment status, and incident VTE. METHODS We used Danish national registries to identify 51 350 persons aged 25-65 years with incident VTE during 1995-2016. For each case, we used incidence density sampling to select five age-, sex-, and index-year-matched controls from the general Danish population (n = 256 750). SES indicators, including education, income, and employment status, were assessed 1 and 5 years before the VTE. We used conditional logistic regression to compute odds ratios (ORs) with 95% confidence intervals (CIs) for VTE according to individual SES indicators and a composite SES score in analyses adjusted for age, sex, and comorbidities. RESULTS Compared with low levels, high educational level (OR 0.74; 95% CI 0.71-0.77), high income (OR 0.70; 95% CI 0.68-0.72), and high employment status (OR 0.66; 95% CI 0.64-0.68) were associated with decreased risk of VTE, even after adjusting for comorbidities. A composite SES score was superior to the individual indicators in assessing VTE risk (OR for high vs. low score: 0.61; 95% CI 0.59-0.63). In sensitivity analysis with SES indicators measured 5 years before the VTE, the risk estimates remained essentially the same. CONCLUSION High levels of both individual SES indicators and a composite SES score were associated with decreased VTE risk.