PRO56 THE GEOGRAPHIC AVAILABILITY OF SUB-SPECIALIZED METABOLIC AND PEDIATRIC TRANSPLANT CARE AND ITS IMPACT ON TREATMENT CHOICE IN PATIENTS WITH UREA CYCLE DISORDERS

Abstract

Urea cycle disorders (UCD) are rare inherited metabolic diseases (IMDs) characterized by episodes of hyperammonemia, which, if untreated, lead to brain damage and death. There are two treatment options for UCD: 1) medical management (MM) with diet and medications, or 2) liver transplant (LT). Both are associated with mortality and morbidity but evidence comparing outcomes is sparse. Patients with IMDs also face geographic access barriers to sub-specialized care, which further complicates treatment decision-making. This study applied Geographic Information System (GIS) technology to examine how the geographic availability of care, as a metric of health care access, impacts treatment choice in this population. Residence data (N=252) was combined with hospital address data in ArcGIS to model geographic proximity to regionalized expert UCD care sites and pediatric LT centers. Proximity was linked to patient disease and treatment history to test the association between geographic availability of sub-specialized care and treatment choice. Interaction terms were integrated to examine how associations change in response to disease severity or control. Analysis found that the odds of LT is 3.22 times higher among patients whose nearest pediatric LT center is one of two considered to deliver the “gold standard” in transplant care. These findings suggest that treatment choice may be driven by the patient’s distance to certain programs where LT as treatment for UCD is strongly supported. Interaction models suggest that treatment decisions among patients with a less severe condition may be even more responsive to the characteristics of their nearest expert institution (OR=4.45). Findings suggest that treatment choice in UCD may be guided by the culture of the institution where patients are geographically able to access care. Researchers and practitioners should strive to better understand the drivers of unwarranted variation in treatment guidance for IMDs and evaluate interventions that address inter-institutional inconsistencies in treatment practice.