Association of depression with long-term mortality in survivors of out-of-hospital cardiac arrest: A population-based longitudinal study

Background: We aimed to identify the associations between depression or anxiety and long-term mortality in survivors of out-of-hospital cardiac arrest (OHCA). Methods: We conducted a retrospective longitudinal cohort study using claims data from the Korean National Health Insurance Service (NHIS) database. We included OHCA patients (aged ≥18 years) who werehospitalized between January 2005 and December 2015 and had survived for 1 year or longer. We extracted the data of patients diagnosed with depression or anxiety within l year. The endpoint waslong-term cumulative mortality. We evaluated long-term mortality in patients with and withouta diagnosis of depression or anxiety. Results: We followed 2,373 OHCA patients for up to 14 years. A total of 397 (16.7%) patients were diagnosed with depression or anxiety, of whom251 (10.6%) and 227 (9.6%) were diagnosed with depression and anxiety, respectively. The incidence of long-term mortality was significantly higher in the group diagnosed with depression or anxiety than in the group without depression or anxiety [141 (35.5%) vs. 534 (27.0%), p=0.001]. We performed multivariate Cox proportional hazards regression,and the adjusted hazard ratios (aHRs) of long-term mortality in total patients with depression or anxiety, patients with depression, and patients with anxiety were 1.41 (95% confidence interval (CI), 1.17-1.70), 1.44 (95% CI, 1.16-1.79), and 1.20 (95% CI, 0.94-1.53), respectively. Conclusions: Among the patients who survived OHCA, those diagnosed with depression or anxiety had higher long-term mortality rates than those without depression or anxiety.