Nationwide Trends in Hospitalizations and In-Hospital Mortality in Granulomatosis With Polyangiitis (Wegener's)

Abstract

Objective: Granulomatosis with polyangiitis (Wegener's) (GPA) is a type of antineutrophil cytoplasmic antibody–associated vasculitis that often entails severe end-organ damage and treatment-related complications that frequently lead to hospitalization and death. Nationwide trends in hospitalizations and in-hospital mortality over the past 2 decades are unknown and were evaluated in this study. Methods: Using the National Inpatient Sample, the largest all-payer inpatient database in the US, trends in hospitalizations with a discharge diagnosis of GPA (formerly Wegener's granulomatosis; International Classification of Disease, Ninth Revision, Clinical Modification code 446.4) between 1993 and 2011 were studied. Analyses were performed using hospital-level sampling weights to obtain US national estimates. Results: From 1993 to 2011, the annual hospitalization rate for patients with a principal diagnosis of GPA increased by 24%, from 5.1 to 6.3 per 1 million US persons (P < 0.0001 for trend); however, in-hospital deaths in this group declined by 73%, from 9.1% to 2.5% (P < 0.0001 for trend), resulting in a 66% net reduction in the annual in-hospital mortality rate. The median length of stay declined by 20%, from 6.9 days in 1993 to 5.5 days in 2011 (P = 0.0002 for trend). Infection was the most common principal discharge diagnosis when GPA was a secondary diagnosis, including among those who died during hospitalization. Conclusion: The findings from these nationally representative, contemporary inpatient data indicate that the in-hospital mortality of GPA has declined substantially over the past 2 decades, while the overall hospitalization rate for GPA increased slightly. Infection remains a common principal hospitalization diagnosis among GPA patients, including hospitalizations resulting in mortality.