Effects of the COVID-19 pandemic on patients with inflammatory joint diseases in Sweden: from infection severity to impact on care provision

Objectives To compare risks for COVID-19-related outcomes in inflammatory joint diseases (IJDs) and across disease-modifying antirheumatic drugs (DMARDs) during the first two waves of the pandemic and to assess effects of the pandemic on rheumatology care provision. Methods Through nationwide multiregister linkages and cohort study design, we defined IJD and DMARD use annually in 2015-2020. We assessed absolute and relative risks of hospitalisation or death listing COVID-19. We also assessed the incidence of IJD and among individuals with IJD, rheumatologist visits, DMARD use and incidence of selected comorbidities. Results Based on 115 317 patients with IJD in 2020, crude risks of hospitalisation and death listing COVID-19 (0.94% and 0.33% across both waves, respectively) were similar during both waves (adjusted HR versus the general population 1.33, 95% CI 1.23 to 1.43, for hospitalisation listing COVID-19; 1.23, 95% CI 1.08 to 1.40 for death listing COVID-19). Overall, biological disease-modifying antirheumatic drugs (bDMARDs)/targeted synthetic disease-modifying antirheumatic drugs (tsDMARDs) did not increase risks of COVID-19 related hospitalisation (with the exception of a potential signal for JAK inhibitors) or death. During the pandemic, decreases were observed for IJD incidence (-7%), visits to rheumatology units (-16%), DMARD dispensations (+6.5% for bDMARD/tsDMARDs and -8.5% for conventional synthetic DMARDs compared with previous years) and for new comorbid conditions, but several of these changes were part of underlying secular trends. Conclusions Patients with IJD are at increased risk of serious COVID-19 outcomes, which may partially be explained by medical conditions other than IJD per se. The SARS-CoV-2 pandemic has exerted measurable effects on aspects of rheumatology care provision demonstrated, the future impact of which will need to be assessed.