Abstract 150: Machine Learning Methodology Predicts Comorbidities are Associated With Increased Total Healthcare Costs Among Patients With Severe Peripheral Artery Disease

Introduction: Peripheral artery disease (PAD) is manifested over a continuum of severity with comorbidities that may significantly increase healthcare costs (HC). Little research has been completed to understand the healthcare resource use (HRU) and HC in this population, specifically among severe PAD patients. We sought to understand the economic burden in this population. Methods: We identified severe PAD patients (rest pain, gangrene or ulceration) from an integrated administrative claims and electronic medical records database (Optum + Humedica 2007-15) with over 7 million patients. The first PAD diagnosis was the index date. Patients were required to be age ≥50 at index date, have clinical activity and continuous enrollment in the 6-month pre-index and 12-month or until death post-index periods. Patients with history of intracranial hemorrhage, stroke and transient ischemic attack were removed. We assessed HRU and all-cause annual total HC in the post-index period or until death, and descriptive analyses, means and SDs. Reverse Engineering and Forward Simulation (REFS TM ) models, an ensemble of Bayesian networks, were machine learned to examine baseline demographic and clinical characteristics and their association with post-index natural log all-cause annual total HC among living patients. We assessed effect estimates across the ensemble using Mean Percentage Change in Costs (MPCC) with SD. Results: The final study sample included 3,189 severe PAD patients. Mean number of all-cause hospitalizations was 1.3 (SD 1.8) and the mean length of stay was 8.0 days (SD 18.2). The mean all-cause annual total HC per patient was $56,973 (SD $91,523). Highly predictive factors associated with increased costs were (MPCC, SD): chronic ulcer of leg or foot (1.9, 0.1), chronic kidney diseases (CKD; 1.9, 0.2), cellulitis and abscess (1.8, 0.2), hypertension (1.6, 0.1), and carditis and cardiomyopathy (1.2, 0.1). Conclusion: In this study, the presence of chronic ulcers in the lower extremities and CKD were two factors most predictive of increased all-cause total HC in a geographically diverse population of severe PAD patients.