Effectiveness of clinical decision support in controlling inappropriate imaging.

BACKGROUND Decision support systems for advanced imaging are being implemented with increased frequency and are mandated under some new governmental health care initiatives. However, evidence of effectiveness in reducing inappropriate imaging utilization is limited. METHODS A retrospective cohort study was performed of the staged implementation of evidence-based clinical decision support built into ordering systems for selected high-volume imaging procedures: lumbar MRI, brain MRI, and sinus CT. Brain CT was included as a control. Imaging utilization rates (number of patients imaged as a proportion of patients with selected clinical conditions) and overall imaging utilization before and after the interventions were determined from billing data from a regional health plan and from the institutional radiology information system. RESULTS The use of imaging clinical decision support was associated with substantial decreases in the utilization rate of lumbar MRI for low back pain (risk ratio, 0.77; 95% confidence interval, 0.87-0.67; P = .0001), head MRI for headache (risk ratio, 0.76; 95% confidence interval, 0.91-0.64; P = .001), and sinus CT for sinusitis (risk ratio, 0.73; 95% confidence interval, 0.82-0.65; P < .0001). Utilization rates for the head CT control group were not significantly changed. There was a corresponding significant decrease in overall imaging volumes (all diagnoses) for lumbar MRI, head MRI, and sinus CT, with no observed effect for the head CT control group. CONCLUSION Targeted use of imaging clinical decision support is associated with large decreases in the inappropriate utilization of advanced imaging tests.