With few population-based studies assessing vasculitis-related mortality, most of which are limited to vasculitis subtypes, researchers examined time trends in in-hospital mortality in patients with vasculitis and compared these trends with those among the general US population using the U.S. National Inpatient Sample (NIS) from 1998-2014. The study team calculated unadjusted in-hospital mortality rates per 1,000 hospitalizations for people with versus without primary vasculitis hospitalizations. Unadjusted in-hospital mortality in primary vasculitis hospitalizations decreased by 43%, from 32.8 per 1,000 in 1998 to 18.7 per 1,000 in 2014, compared with a 24.5% reduction in deaths for all NIS claims without vasculitis, from 28.1 to 21.2 per 1,000. Age- and sex-adjusted in-hospital mortality decreased in primary vasculitis hospitalizations, from 27.3 per 1,000 claims in 1998 to 19.1 in 2014, as well as in non-vasculitis hospitalizations, from 15.1 to 13.2 per 1,000 in 2014. These rates occurred despite primary vasculitis hospitalizations per year remaining fairly constant throughout the study period. The age- and sex-adjusted mortality rate gap between those with versus without vasculitis narrowed.