Effect of COVID‐19 inpatients with cognitive decline on discharge after the quarantine period: A retrospective cohort study

Abstract Background A new SARS‐CoV‐2 variant, Omicron, was reported on November 14, 2021, and it altered the COVID‐19 epidemic with a different peak timing by region in Japan. Residents in the Hiroshima prefecture, especially the vulnerable elderly, were threatened by this wave in advance of many other prefectures. We evaluated the effect of cognitive decline on discharge extension after the quarantine period. Methods Participants of this retrospective cohort study were patients who were admitted to the care unit for COVID‐19 treatment at Hiroshima University Hospital between January 1, 2022, and March 1, 2022 (60 days). Our primary outcome was the extended length of stay (LOS) in the hospital after the quarantine period (10 days after onset). A negative binomial regression analysis was performed to assess the extended LOS of patients with cognitive decline, adjusting for age classification, gender, and severity of COVID‐19. Results The total number of participants was 74. Per the level of cognitive function, there were 56 independent participants, 5 mild declines, and 13 severe declines. For the negative binomial regression analysis, the exponentiated coefficient of mild cognitive decline was 3.05 (95% confidential interval [CI]: 1.43–6.49) and that of severe cognitive decline was 1.95 (95% CI: 1.09–3.53). Conclusions Mild cognitive decline and severe cognitive decline elevated the risk of extended LOS after COVID‐19 patients finished the quarantine period.