Male Sex, Diabetes Mellitus, and an Unvaccinated Status as Deteriorating Factors for Coronavirus Disease 2019 in Patients with Rheumatic Diseases: A Single-center Analysis in the North Kanto Region of Japan During the Omicron Variant Period.

Objective This study aimed to analyze the risk factors for coronavirus disease 2019 (COVID-19) deterioration in patients with rheumatic disease. Methods We conducted a retrospective study of patients with rheumatic disease who were admitted to our division for COVID-19, as well as those who were confirmed to have developed COVID-19 at either an outpatient or in-hospital onset during the Omicron variant period between January 2022 and December 2023. We retrospectively collected data on the prefectures of residence, the underlying rheumatic diseases, medications, periods of COVID-19 diagnosis, total vaccination doses, severity, COVID-19 treatments, outcomes, and comorbidities from medical records. For inpatients, the blood test results at the time of diagnosis or admission were also collected. We conducted a multivariate logistic regression analysis to identify the deteriorating factors for COVID-19. Results We identified 78 patients from the North Kanto region of Japan who were diagnosed with COVID-19. Among them, 33 were hospitalized, two were diagnosed with COVID-19 in our outpatient division, and 43 were diagnosed at other hospitals. The disease was mild, moderate, severe, and critical in 61 (78.2%), five (6.4%), 10 (12.8%), and two (2.6%) patients, respectively. The significant risk factors for moderate-to-critical disease were a male sex (p=0.012), an unvaccinated status (p=0.031), and diabetes mellitus (p=0.018). No blood test results were significant according to the multivariate analysis. Conclusion Most patients with COVID-19 and rheumatic diseases had favorable outcomes during the Omicron period. The management of comorbidities, such as diabetes mellitus, and the facilitation of vaccination are important for preventing severe COVID-19.