Association Between Low Socioeconomic Position and Higher Mortality in Patients Who Are Mechanically Ventilated in Denmark

Background Low socioeconomic position (SEP) generally is associated with poor health, but whether it is associated with mortality in critically ill patients is unclear. Research Question Is low SEP associated with mortality among Danish adults receiving invasive mechanical ventilation (IMV)? Study Design and Methods This population-based cohort study included nonsurgical patients ≥ 25 years of age receiving incident IMV from January 2005 through December 2022 using data from national registries. We evaluated indicators of SEP by age: household income (25-64 years) or liquid assets (≥ 65 years); education; and employment (25-64 years). The main outcome was 1-year mortality. We performed descriptive analyses and computed hazard ratios (HRs) via Cox proportional hazards regression with age- and sex-adjustment and with propensity score weighting. Results Among those 25 to 64 years of age (n = 23,451), crude 1-year mortality for low-income, medium-income, and high-income groups was 39.5%, 40.7%, and 36.2%, respectively. Patients with low vs high income and with low vs high education showed elevated weighted HRs: 1.50 (95% CI, 1.24-1.82) and 1.24 (95% CI, 1.14-1.36), respectively. Unemployed male patients showed higher mortality than employed male patients (HR, 1.28; 95% CI, 1.11-1.48); results were null for female patients. Among patients ≥ 65 years of age (n = 31,636), crude 1-year mortality for low-income, medium-income, and high-income groups was 65.0%, 63.6%, and 59.9%, respectively. A slightly increased hazard of mortality was seen for older patients with low vs high income (HR, 1.15; 95% CI, 1.08-1.22). Interpretation Our results show that although Danish residents have access to tax-funded health care, we observed evidence of increased mortality hazard among patients receiving IMV with lower SEP, particularly in younger adults.