Multicenter Evaluation of Risk and Prognostic Factors for COVID-19 Omicron Variant in Meguro Home Medical Care: A Retrospective Cohort Study

Background: Old age, comorbidities, and vaccination status are known risk factors for hospitalization and mortality in COVID-19 patients. However, the clinical course and outcomes among those receiving home medical care remain unclear. Methods: We retrospectively reviewed 2598 patients who received doctor-visiting care from 10 clinics in Meguro-city, Tokyo, Japan, between January 2022 and September 2023. Among them, 194 patients diagnosed with COVID-19 after initiating home care were analyzed. Patients were classified into hospitalization versus non-hospitalization groups, and survival versus non-survival groups for background comparison. Results: Among the 194 patients enrolled, COVID-19 severity emerged as a significant risk factor for hospitalization and mortality. Meanwhile, the level of daily life independence for disabled elderly patients was an independent risk factor for hospitalization but not for survival. A ROC analysis revealed that the “optimal” cutoff value for the daily life independence level of disabled associated with hospitalization was Rank “B1,” which was a person who requires some assistance living indoors and spends most of the day in bed but can sit up. The 3- and 6-month survival rates for all enrolled patients were 89.1% and 83.9%, respectively. The non-survival group had a significantly higher proportion of patients with malignancies and a higher Charlson comorbidity index than the survival group. Conclusions: In home medical care patients, severe COVID-19 infection and lower independence increase hospitalization risk, while malignancies and comorbidities affect mortality, highlighting the importance of assessing functional status and comorbidity profiles to guide clinical decisions for COVID-19 management in home care settings.