Risk Factors Associated with Progression to Severe COVID-19 and Mortality among Residents of Long-term Care Facilities in South Korea

Background: During the early stages of the COVID-19 pandemic, many residents of longterm care facilities (LTCFs) in various countries were infected with COVID-19, leading to high mortality.This study aimed to identify risk factors associated with severe disease progression and mortality among LTCF residents to mitigate the impact of COVID-19 on this vulnerable population.Methods: We analyzed risk factors for severe disease and mortality in 224,983 patients with COVID-19 aged 50 years or older, focusing specifically on 4,442 LTCF residents.Results: Logistic regression analysis showed that, among all patients aged 50 and older, severe progression was associated with LTCF residence (OR: 1.29, 95% CI: 1.15-1.44),older age, male sex, higher Charlson Comorbidity Index (CCI), and having received fewer than three doses of COVID-19 vaccine.Mortality within 30 days was associated with LTCF residence (OR: 2.04, 95% CI: 1.86-2.24),older age, male sex, higher CCI, under-vaccination, and receipt of medical aid.Among LTCF residents, male sex and lack of COVID-19 vaccination (OR: 4.37, 95% CI: 2.77-6.91)were significantly associated with increased risk of severe progression.Mortality among LTCF residents was associated with older age, male sex, absence of vaccination (OR: 6.18, 95% CI: 4.40-8.68),no hospitalization or emergency room visit within 30 days after diagnosis, and an LTCF stay of longer than one year (OR: 1.51, 95% CI: 1.09-2.09).A higher number of medical staff in LTCF was significantly associated with lower mortality (OR: 0.71, 95% CI: 0.55-0.91).Conclusion: LTCF residents shared similar risk factors for severe COVID-19 progression and mortality as the general population.Timely medical intervention for LTCF residents may help reduce severe outcomes and prevent death.