Trends in severe outcomes in SARS-CoV-2-positive hospitalized patients with rheumatic diseases: a monocentric observational and case-control study in northern Italy

Rheumatic disease patients are at greater risk of infection due to their disease, comorbidities, and immunosuppressive therapy. COVID-19 outcomes in this patient setting appeared to be similar to those of the general population. However, data on this topic were mainly related to small studies on a limited number of patients. Consequently, to date, this field remains poorly explored, particularly in the pre-vaccine era. This monocentric study aimed to describe the intrahospital mortality in rheumatic patients with SARS-CoV-2 consecutively hospitalized from 21 February to 31 December 2020, before anti-SARS-CoV-2 vaccine administration spread, compared with non-rheumatic patients. Of 2491 included patients, 65 [3%, median (interquartile range) age 75 (64.76-82.239 years, 65% women] were suffering from rheumatic diseases. A total of 20 deaths were reported [case fatality rate 31%, 95% confidence interval (CI): 19-42] compared with 433 deaths (19%, 95% CI: 17-20) in patients without rheumatic diseases (p=0.024). However, the rheumatic disease was not associated with a significant increase in univariate mortality hazards (hazard ratio 1.374, 95% CI: 0.876-2.154), and after adjustment (hazard ratio 1.199, 95% CI: 0.759-1.894) by age, sex and Charlson comorbidity index. The incidence of intensive care unit admission, death, and discharge in the case-control study was comparable between rheumatic and non-rheumatic patients. The presence of rheumatic diseases in SARS-CoV-2-hospitalized patients did not represent an independent risk factor for severe disease or mortality.