Impact of a Health Information Technology–Enabled Appropriate Use Criterion on Utilization of Emergency Department CT for Renal Colic

The purpose of this study was to evaluate the impact of an appropriate use criterion (AUC) for renal colic based on local best practice, implemented as electronic clinical decision support (CDS), on the emergency department (ED) use of CT for patients with suspected nephrolithiasis.This retrospective cohort study was performed in the EDs of a level I trauma center (study site) and local comparable hospital (control site). An AUC for patients younger than 50 years with a history of uncomplicated nephrolithiasis presenting with renal colic was developed by an interdisciplinary emergency medicine, emergency radiology, and urology team and embedded as CDS. AUC-consistent CT of ureter requests received no CDS alert. Otherwise, the orderer was alerted to consider a trial of symptomatic control or discharge without CT. A natural language processing tool mined ED notes for visits in September 2010-February 2012 (before AUC implementation) and April 2013-September 2014 (1 year after implementation) for concept unique identifiers of flank tenderness or renal or ureteral pain. Manual review excluded noneligible cases; the others were reviewed by a multidisciplinary team. Chi-square tests were used to assess for CT rate differences, the primary outcome.The final sample included 467 patients (194 study site) before and 306 (88 study site) after AUC implementation. The study site's CT of ureter rate decreased from 23.7% (46/194) to 14.8% (13/88) (p = 0.03) after implementation of the AUC. The rate at the control site remained unchanged, 49.8% (136/273) versus 48.2% (105/218) (p = 0.3).Implementing an AUC based on local best practice as CDS may effectively curb potential imaging overuse in a subset of ED patients with renal colic unlikely to have a complicated course or alternative dangerous diagnosis.