Does clinical decision support system promote expert consensus for appropriate imaging referrals? Chest-abdominal-pelvis CT as a case study.

Objectives: We assessed the appropriateness of chest-abdominal-pelvis (CAP) CT scan use in the Emergency Department (ED), based on expert physicians and the ESR iGuide, a clinical decision support system (CDSS).

Methods: A retrospective cross-study was conducted. We included 100 cases of CAP-CT scans ordered at the ED. Four experts rated the appropriateness of the cases on a 7-point scale, before and after using the decision support tool.

Results: Before using the ESR iGuide the overall mean rating of the experts was 5.2 ± 1.066, and it increased slightly after using the system (5.85 ± 0.911 (p < 0.01)). Using a threshold of 5 (on a 7-level scale), the experts considered only 63% of the tests appropriate before using the ESR iGuide. The number increased to 89% after consultation with the system. The degree of overall agreement among the experts was 0.388 before ESR iGuide consultation and 0.572 after consultation. According to the ESR iGuide, for 85% of the cases, CAP CT was not a recommended option (score 0). Abdominal-Pelvis CT was "usually appropriate" for 65 out of the 85 (76%) cases (score 7-9). 9% of the cases did not require CT as first exam modality.

Conclusions: According to both the experts and the ESR iGuide, inappropriate testing was prevalent, in terms of both frequency of the scans and also inappropriately chosen body regions. These findings raise the need for unified workflows that might be achieved using a CDSS. Further studies are needed to investigate the CDSS contribution to the informed decision-making and increased uniformity among different expert physicians when ordering the appropriate test.