Incidence and prevalence of idiopathic inflammatory myopathies in Sweden: a nationwide population-based study

Abstract

We present nationwide register-based incidence and prevalence estimates for IIM, robust across three different case definitions. In contrast to many other reports, we did not find incidence by age to be bimodal and we found no explanation of incidence variation across education and residency. These register-based case definitions can be included in future population-based studies to better understand disease aetiology, risk factors and comorbidities.