Abstract: BRIEF REPORT Identification of Risk Factors for COVID-­19 Hospitalization in Patients with Anti-­Rheumatic Drugs: Results from a Multicenter Nested Case Control Study Merel A. A. Opdam1,*, Sophie Benoy2, Lise M. Verhoef1, Sandra Van Bijnen3, Femke Lamers-­Karnebeek4, René A. M. Traksel2, Petra Vos5, Alfons A. den Broeder1 and Jasper Broen2 Patients with inflammatory rheumatic diseases (IRDs) do not have an increased risk for coronavirus disease 2019 (COVID-­19) compared with the general population. However, it remains uncertain whether subgroups of patients with IRD using different immunosuppressive antirheumatic drugs carry a higher risk for severe COVID-­19 compared with other patients with IRD. The aim of this study is to identify risk factors for severe COVID-­19, requiring hospitalization in patients with IRD. This is a multicenter nested case control study conducted in the Netherlands. Cases are hospital known patients with IRD requiring hospitalization for COVID-­19 between March 1, 2020, and May 31, 2020. Controls are hospital known patients with IRD not requiring hospitalization for COVID-­19 in this period, included at a 4:1 ratio. Patient, disease, and treatment characteristics were extracted from electronic medical records and a questionnaire. Potential risk factors were analyzed using unconditional logistic regression, corrected for confounders and multiple testing. Eighty-­one cases and 396 controls were included. General risk factors of older age and obesity apply to patients with IRD as well (odds ratio (OR) for age ≥75 3.5, 95% confidence interval (CI) 1.9–­6.3, OR for body mass index ≥40 4.5, 95% CI 1.5–­14). No significantly increased ORs for COVID-­19 hospitalization were found for any antirheumatic agent or IRD. A protective effect was found for use of methotrexate (OR 0.53, 95% CI 0.31–­0.92). In conclusion, similar to the general population, elderly and obese patients with IRD have a higher risk for hospitalization for COVID-­19. We did not identify a specific antirheumatic agent or IRD to increase the risk of COVID-­19 hospitalization in patients with IRD, except for a possible protective effect of methotrexate. Study Highlights WHAT IS THE CURRENT KNOWLEDGE ON THE TOPIC?  The majority of the studies performed on coronavirus disease 2019 (COVID-­19) risk in inflammatory rheumatic diseases (IRDs) show no increased risk for severe COVID-­19 in these patients, who often receive immunosuppressive antirheumatic drugs. Case-­control studies are, however, a scarce commodity and most of the data is derived from registry-­based studies. WHAT QUESTION DID THIS STUDY ADDRESS?  In this study, we aimed to determine whether certain patients with IRD carry a higher risk for COVID-­19-­related hospitalization, for example, due to the use of antirheumatic agents. WHAT DOES THIS STUDY ADD TO OUR KNOWLEDGE?  The overall finding that no specific antirheumatic drugs or IRD enhances the risk of severe COVID-­19, requiring hospitalization, is reassuring for patients and medical personnel. Additionally, the finding that methotrexate has a possible protective effect for severe COVID-­19 is of high interest in an enduring pandemic and still imperfect protection by vaccination. HOW MIGHT THIS CHANGE CLINICAL PHARMACOLOGY OR TRANSLATIONAL SCIENCE?  Our finding might spark interest in further investigations into methotrexate as an avenue for prospective clinical investigation in COVID-­19 treatment and prevention. 1 Department of..