Practice patterns in the emergency care of kidney stone patients: an analysis of the National Hospital Ambulatory Medical Care Survey (NHAMCS).

INTRODUCTION: The emergency department (ED) is a common setting for evaluation of patients with urolithiasis based on acute symptoms and a propensity for recurrent disease. We sought to characterize practice patterns in the emergency treatment of stone disease, and to identify potential disparities in care based on non-medical factors.
MATERIALS AND METHODS: We performed a cross-sectional analysis of ED visits using the National Hospital Ambulatory Medical Care Survey from 2005-2009. Visits with a diagnosis of urolithiasis were identified. The associations between patient, provider and institutional characteristics were analyzed with regard to timing of clinical assessment, use of diagnostic imaging, and use of medical expulsive therapy (MET).
RESULTS: The likelihood of a delay in clinical assessment ranged from 30.8%-37.9%. Neither patient nor provider characteristics were associated with a delay in assessment, although urban location (p = 0.004) was more likely, and proprietary ownership was less likely (p = 0.002) to be associated with delay. Factors associated with use of CT included ambulance arrival (p = 0.043), initial ED visit (p = 0.000), and Northeast region (p = 0.030). Patients seen by a resident/intern were more likely to receive MET (p = 0.028). Overall, 10.8% of patients were presenting for follow up treatment, and 7.1% had been seen in the same ED within the last 72 hours.
CONCLUSIONS: Kidney stones are associated with a high rate of repeated presentations to the ED. Certain non-medical factors did impact details of management. Future efforts should focus on optimizing clinical pathways to improve the efficiency of acute care for kidney stone patients.