Background ANCA-associated vasculitis (AAV) is associated with severe end-organ damage (e.g., renal failure) and treatment-related complications (e.g., severe infection) which often lead to hospitalization. However, no data on recent hospitalization trends and associated mortality are available1.
Objectives We evaluated recent trends in nationwide hospitalization, cost, and in-hospital mortality among patients with AAV.
Methods We used the National Inpatient Survey (NIS) which is the largest all-payer inpatient database in the US. We studied all hospitalizations with a discharge diagnosis of AAV (ICD 9: 446.4) between 1993 and 2011. We investigated trends in hospitalization, cost, and mortality by comparing AAV to overall inpatient hospitalization trends. Analyses were performed using hospital-level sampling weights provided by the NIS to obtain US national estimates.
Results From 1993 to 2011, the rate of hospitalization for AAV increased from 1.9/100,000 persons to 4.5/100,000 persons (P-for-trend <0.0001). This was primarily driven by a rapid increase in the hospitalization rate among those with a secondary discharge diagnosis of AAV (1.4/100,000 persons to 3.9/100,000 persons, P<0.0001). Over the study period, there was a significant decline in in-hospital death from 9.9% (±1.2%) in 1993 to 3.5% (±0.4%) in 2011 (P-for-trend <0.0001). Overall, the annual relative change in AAV mortality was - 4.8% (95% CI: -5.6 to -4.0%). This was a significantly greater decline than overall US inpatient hospitalization mortality (-2.18%, 95% CI -2.19% to -2.17%). Infection was the most common principal diagnosis when AAV was a secondary diagnosis.
Conclusions Between 1993 and 2011, there was a significant decline in in-hospital mortality among those admitted with a diagnosis of AAV. This decline was significantly greater than that of the overall US in-hospital mortality rate. The declining in-hospital mortality rate may be due to earlier recognition of GPA, shifts in treatment that emphasize less cyclophosphamide use and more tempered use of glucocorticoids, and secular trends in the management of infections and end-organ complications2.
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Disclosure of Interest None declared