Analysis of Low Appropriateness Score Exam Trends in Decision Support–based Radiology Order Entry System

Purpose Awareness of imaging utilization increased after implementation of Radiology Order Entry with decision support systems (ROE-DS). Our hypothesis is few exams with low Clinical Appropriateness Score (CAS) on ROE-DS are performed. Clinical indications of exams with CAS less than 3 (9-point scale) were re-reviewed and reports analyzed. Materials and Methods Structured Query Language–based query retrieved exams with CAS less than 3 in ROE-DS from January 2007 to December 2011. Reasons provided by physicians for ordering these exams and reports of exams performed were analyzed. For each indication, number of exams ordered and performed was calculated. Statistical significance was assessed using Student's t test and χ² analysis (P <.05). Results From 445,984 exams, 12,615 exams (2.8%) had CAS less than 3, and 7,956 exams (63%) were performed. Reasons for ordering of 12,615 low CAS exams were as follows: Requests by physician specialists without further explanation (4,516 = 35.8%), notation of special clinical circumstances (2,877 = 22.8%), requests by nonphysician staff without further explanation (1,383 = 10.9%), absence of suspected finding on previous modality (1,099 = 8.7%), patient preference (737 = 5.8%), and requests based on radiologists’ recommendations (706 = 5.6%). Difference between male and female (male < female) preferences for low CAS exams was statistically significant (P <.01). Imaging outcome was highest for extremity MRI cases (66.7%; P <.01). Conclusion Less than 3% of exams ordered had low CAS and about two-thirds of these were performed. Most common indication for ordering these exams was physician specialist request based on opinion of medical necessity without specification. Extremity MRI constituted the highest positive findings for low CAS exams performed.