Use of Imaging During Emergency Department Visits for Low Back Pain

OBJECTIVE. Back pain is one of the most common reasons for adult patients 18-65 years old to seek emergency care. Use of imaging for patients without so-called red flags (trauma, malignancy, or infection) may result in potentially unnecessary costs and radiation exposure. The aim of this study was to investigate the use of imaging for patients with emergency visits for low back pain. MATERIALS AND METHODS. Emergency department visits for patients with low back pain billed to insurance were identified by querying a national commercial claims and encounters database for patients 18-64 years old. Patients with concomitant encounter diagnoses suggestive of trauma or those with prior visits for back pain were excluded. Imaging modalities (radiography, CT, and MRI) were identified by Current Procedural Terminology codes. RESULTS. A total of 134,624 encounters met inclusion criteria. Imaging was obtained in 44,405 (33.7%) visits and decreased from 34.4% to 31.9% between 2011 and 2016 (odds ratio per year, 0.98 [95% CI, 0.98-0.99]; p < 0.001). During the study period, 30.9% of patients underwent radiography, 2.7% of patients underwent CT, and 0.8% of patients underwent MRI for evaluation of low back pain. The use of imaging varied significantly by geographic region (p < 0.001), with patients in the southern United States undergoing 10% more imaging than patients in the western United States. CONCLUSION. The use of imaging for the initial evaluation of patients with low back pain in the emergency department continues to occur at a high rate, in approximately one in three new emergency visits for low back pain in the United States.