Admission Rates and Costs Associated with Emergency Presentation of Urolithiasis: Analysis of the Nationwide Emergency Department Sample 2006-2009

Background and Purpose: We sought to examine a large nationwide (United States) sample of emergency department (ED) visits to determine data related to utilization and costs of care for urolithiasis in this setting. Methods: Nationwide Emergency Department Sample was analyzed from 2006 to 2009. All patients presenting to the ED with a diagnosis of upper tract urolithiasis were analyzed. Admission rates and total cost were compared by region, hospital type, and payer type. Numbers are weighted estimates that are designed to approximate the total national rate. Results: An average of 1.2 million patients per year were identified with the diagnosis of urolithiasis out of 120 million visits to the ED annually. Overall average rate of admission was 19.21%. Admission rates were highest in the Northeast (24.88%), among teaching hospitals (22.27%), and among Medicare patients (42.04%). The lowest admission rates were noted for self-pay patients (9.76%) and nonmetropolitan hospitals (13.49%). The smallest increases in costs over time were noted in the Northeast. Total costs were least in nonmetropolitan hospitals; however, more patients were transferred to other hospitals. When assessing hospital ownership status, private for-profit hospitals had similar admission rates compared with private not-for-profit hospitals (16.6% vs 15.9%); however, costs were 64% and 48% higher for ED and inpatient admission costs, respectively. Conclusions: Presentation of urolithiasis to the ED is common, and is associated with significant costs to the medical system, which are increasing over time. Costs and rates of admission differ by region, payer type, and hospital type, which may allow us to identify the causes for cost discrepancies and areas to improve efficiency of care delivery.