Appropriateness of lumbar spine imaging in patients presenting to the emergency department with low back pain in a Western Australian tertiary hospital

BackgroundThe Australian Rheumatology Association identified the use of imaging in patients with low back pain without indication of serious pathology as a low-value practice.AimsTo determine the appropriateness of diagnostic lumbar spine imaging requests in patients with low back pain presenting to a Western Australian hospital's emergency department.MethodsWe conducted a retrospective review of all adult patients (18 years and older) who presented with low back pain to the Fiona Stanley Hospital emergency department from 1 July 2020 to 31 December 2020. The appropriateness of the imaging requests was judged using the American College of Radiology's Appropriateness Criteria. The number and proportion of appropriate and inappropriate lumbar spine imaging requests were reported overall and by imaging modality together with reasons for the judgements.ResultsA total of 1459 patients were included. Three hundred eight patients (21.1%) received lumbar spine imaging requests, with 350 diagnostic imaging requests eligible for analysis. Two hundred eighty (80.0%) imaging requests were judged to be appropriate (194/253 (76.7%) plain radiographs, 57/66 (86.4%) computed tomography, 29/31 (93.5%) magnetic resonance imaging). The most common reasons for an appropriate imaging request were suspected vertebral fracture (n = 223, 79.6%), followed by malignancy (n = 26, 9.3%). Of the 70 inappropriate imaging requests, 62 (88.6%) requests occurred in the absence of alerting features and eight (11.4%) requests were the wrong choice of modality.ConclusionsFour in five lumbar spine imaging requests for investigating low back pain were appropriate. Of the inappropriate requests, the most common reason was the absence of alerting features, while a small number were the incorrect imaging modality.