FRI0296\u2005INPATIENT PREVALENCE, MORTALITY, EXPENDITURES AND COMORBIDITIES OF POLYARTERITIS NODOSA: NATIONWIDE INPATIENT SAMPLE 2014

Abstract

Background Polyarteritis nodosa (PAN) is a systemic necrotizing vasculitis that characteristically affects medium-sized arteries of the intestine, kidneys and soft tissue [1]. Little is known about the inpatient burden, expenditures and association with comorbidities of PAN. Objectives To investigate the inpatient prevalence, expenditures and comorbidities of patients with PAN using a national inpatient database. Methods Patients with PAN were identified from the Nationwide Inpatient Sample (NIS) database of the years 2014 using ICD-9 diagnostic code. NIS is a publicly available inpatient database that contained data of over 7 million hospital stays, which are a 20% stratified sample of over 4,000 non-federal acute care hospitals across all the regions of the United States (US). Data on patient characteristics, comorbidities, resource utilization and expenditures was collected. The primary outcome was determining the inpatient prevalence of PAN in hospitalized patients in the US. Secondary outcomes included determining inpatient mortality, inpatient morbidity (measured by shock, ICU admission and multi-organ failure), comorbidities, hospital length of stay (LOS) and total hospital costs and charges. The most common reasons for hospitalization were abstracted utilizing the top principal diagnoses in patients with PAN. A cohort of patients without PAN was also identified from the same database to serve as comparators for analysis of comorbidities. Multivariate regression analysis was used to adjust for age, gender, ethnicity, Charlson Comorbidity Index, income, hospital region, location, size and teaching status. Results A total of 5,255 patients with PAN were included in the study. The mean age was 58.8 years, and 57% were female. The top reasons for hospitalization were PAN itself (15.3%), sepsis (6.9%), acute kidney injury (4.8%) and acute respiratory failure (2.5%). For the primary outcome, the inpatient prevalence of PAN was found to be 14.9 cases per 100,000 admissions. For secondary outcomes, patients with PAN displayed increased adjusted odds of mortality (OR:1.60, p<0.01), shock (OR:1.81, p<0.01), ICU admission (OR:2.06, p<0.01) and multiorgan failure (OR:3.45, p<0.01) compared to patients without PAN. Patients with PAN also displayed significantly higher hospital costs (additional adjusted mean [aAM]: $10,780, p<0.01), hospitalization charges (aAM: $39,915, p<0.01) and LOS (aAM: 4.2 days, p<0.01) compared to patients without PAN. Patients with PAN displayed a significant association with several comorbidities ( Table 1 ). Conclusion The inpatient prevalence of PAN was higher than what would be expected from the overall prevalence. The mean total hospital costs and total hospitalization charges for patients with PAN were higher than patients without PAN. Analysis of comorbidities found significantly higher odds of several comorbidities even after adjusting for potential confounders. Reference: [1] Forbess L, Bannykh S. Polyarteritis nodosa. Rheum Dis Clin N Am2015;41:33-46Table 1 Adjusted ORs comparing the prevalence of comorbidities between patients with PAN versus patients without PAN Adjusted odds ratio 95% CI p-value DVT 2.07 1.60-2.66 <0.01 PE 2.12 1.62-2.78 <0.01 AMI 1.27 0.79-2.04 0.32 CHF 1.10 0.92-1.32 0.32 Arrythmia 1.05 0.86-1.29 0.61 Peripheral vascular disease 0.86 0.61-1.19 0.36 Acute kidney injury 4.14 3.54-4.85 <0.01 Chronic kidney disease 9.70 7.69-12.22 <0.01 ESRD 5.51 4.41-6.88 <0.01 Intestinal perforation 3.78 1.59-9.01 <0.01 HBV infection 5.01 2.80-8.95 <0.01 HCV infection 1.65 1.12-2.42 0.01 Sepsis 1.87 1.54-2.28 <0.01 Disclosure of Interests None declared