Incidence and severeness of COVID-19 hospitalisation in patients with inflammatory rheumatic disease: a nationwide cohort study from Denmark

Cordtz, René; Lindhardsen, Jesper; Soussi, Bolette G; Vela, Jonathan; Uhrenholt, Line; Westermann, Rasmus; Kristensen, Salome; Nielsen, Henrik; Torp-Pedersen, Christian; Dreyer, Lene

OBJECTIVES: To estimate the incidence of COVID-19 hospitalisation in patients with inflammatory rheumatic disease (IRD); in patients with rheumatoid arthritis (RA) treated with specific DMARDs; and the incidence of severe COVID-19 infection among hospitalised patients with RA. METHODS: A nationwide cohort study from Denmark between 1 March to 12 August 2020. The adjusted incidence of COVID-19 hospitalisation was estimated for patients with RA; spondyloarthritis including psoriatic arthritis; connective tissue disease; vasculitides; and non-IRD individuals.Further, the incidence of COVID-19 hospitalisation was estimated for patients with RA treated respectively non-treated with TNF-inhibitors, hydroxychloroquine, or glucocorticoids.Lastly, the incidence of severe COVID-19 infection (intensive care, acute respiratory distress syndrome, or death) among hospital-admitted patients was estimated for RA and non-IRD individudals. RESULTS: Patients with IRD (n = 58,052) had an increased partially adjusted incidence of hospitalisation with COVID-19 compared with the 4.5 million people in the general population (HR 1.46, 95%CI 1.15 to 1.86) with strongest associations for patients with RA (n = 29,440, HR 1.72, 95%CI 1.29 to 2.30) and vasculitides (n = 4072, HR 1.82, 95%CI 0.91 to 3.64). There was no increased incidence of COVID-19 hospitalisation associated with TNF-inhibitor, hydroxychloroquine nor glucocorticoid use. COVID-19 admitted patients with RA had a HR of 1.43 (95% CI 0.80 to 2.53) for a severe outcome. CONCLUSION: Patients with IRD were more likely to be admitted with COVID-19 than the general population, and COVID-19 admitted patients with RA could be at higher risk of a severe outcome. Treatment with specific DMARDs did not affect the risk of hospitalisation.