Effect of an ultrasound-first clinical decision tool in emergency department patients with suspected nephrolithiasis: A randomized trial.

INTRODUCTION: Previously, we found that the use of ultrasonography for patients with suspected nephrolithiasis resulted in similar outcomes and less radiation exposure vs. CT scan. In this study, we evaluated the implementation of an ultrasound-first clinical decision support (CDS) tool in patients with suspected nephrolithiasis. METHODS: This randomized trial was conducted at an academic emergency department (ED). We implemented the ultrasound-first CDS tool, deployed when an ED provider placed a CT order for suspected nephrolithiasis. Providers were randomized to receiving the CDS tool vs. usual care. The primary outcome was receipt of CT during the index ED visit. Secondary outcomes included radiation dose and ED revisit. RESULTS: 64 ED Providers and 254 patients with suspected nephrolithiasis were enrolled from January 2019 through Dec 2020. The US-First CDS tool was deployed for 128 patients and was not deployed for 126 patients. 86.7% of patients in the CDS arm received a CT vs. 94.4% in the usual care arm, resulting in an absolute risk difference of -7.7% (-14.8 to -0.6%). Mean radiation dose in the CDS arm was 6.8 mSv (95% CI 5.7-7.9 mSv) vs. 6.1 mSv (95% CI 5.1-7.1 mSv) in the usual care arm. The CDS arm did not result in increased ED revisits, CT scans, or hospitalizations at 7 or 30 days. CONCLUSIONS AND RELEVANCE: Implementation of the US-first CDS tool resulted in lower CT use for ED patients with suspected nephrolithiasis. The use of this decision support may improve the evaluation of a common problem in the ED. TRIAL REGISTRATION: ClinicalTrials.gov#NCT03461536.