Serious mental illness and in-hospital mortality among hospitalized patients with acute COVID-19: A large-database analysis in Japan

OBJECTIVE: The association of serious mental illness (affective or non-affective psychotic disorders) with higher mortality in patients infected with acute coronavirus disease 2019 (COVID-19) has been suggested. Although this association remains significant after adjusting for medical comorbidities in previous studies, admission clinical status and treatment modalities should be considered as important confounding factors. METHODS: We aimed to assess whether serious mental illness is associated with in-hospital mortality, in patients with COVID-19 by adjusting for comorbidities, admission clinical status, and treatment modalities. Our nationwide cohort in Japan included consecutive patients admitted to 438 acute care hospitals for laboratory-confirmed acute COVID-19 from January 1, 2020 to November 30, 2021. RESULTS: Of 67,348 hospitalized patients (mean [standard deviation] age, 54 [18.6] years; 3891 [53.0%] female), 2524 patients (3.75%) had serious mental illness. In-hospital mortality was 282/2524 (11.17%) among patients with serious mental illness, while it was 2118/64,824 (3.27%) in other patients. In the fully adjusted model, serious mental illness was significantly associated with in-hospital mortality (odds ratio, 1.49; 95% CI, 1.27–1.72). E-value analysis confirmed the robustness of the results. CONCLUSION: Serious mental illness remains a risk for mortality in acute COVID-19 after adjusting for comorbidities, admission clinical status, and treatment modalities. Vaccination, diagnosis, early assessment and treatment should be prioritized for this vulnerable group.