Long-term physical and mental health effects of unresolved disaster-related bereavement: evidence from an 8-year propensity score–matched cohort study

<b>Background:</b> Evidence on the long-term mental and physical health effects of disaster-related bereavement remains limited.<b>Objective:</b> To compare long-term healthcare utilisation and disease incidence among individuals bereaved in the Sewol ferry disaster with matched controls.<b>Method:</b> This retrospective cohort study used Korean National Health Insurance data to match 388 bereaved individuals with 1,552 controls. Healthcare utilisation and disease incidence were examined over three years pre-disaster and eight years post-disaster using difference-in-differences and Cox proportional hazards models.<b>Results:</b> Psychiatric outpatient utilisation among the bereaved increased from 10% pre-disaster to 38% in year 1, stabilised around 20%, and rose again to 38% in year 8, whereas controls showed a gradual increase to 22%. Difference-in-differences analyses demonstrated significantly higher psychiatric outpatient visits in the bereaved group, with excess visits of 2.87 (95% CI 1.52-4.22) in years 1-3, 1.86 (0.51-3.21) in years 4-6, and 1.56 (0.21-2.91) in years 7-8. Psychiatric admissions also increased significantly across post-disaster periods. Physical outpatient visits showed delayed excess increases in years 4-6 and 7-8. Cox models indicated elevated risks for infectious, benign neoplastic, endocrine, mental, neurological, digestive, dermatological, and musculoskeletal disorders, as well as abnormal findings and injury.<b>Conclusions:</b> Eight years after the disaster, bereaved individuals continued to exhibit persistent mental health problems and greater physical healthcare utilisation. These findings highlight the need for long-term, integrated support addressing both mental and physical health beyond the immediate aftermath of disasters.