An impact analysis of the NEXUS Chest CT clinical decision rule

The NEXUS Chest CT clinical decision rules (CDRs) have been proposed to safely guide selective chest CT use in blunt trauma evaluation. We conducted a cost-effectiveness analysis of the NEXUS Chest CT CDR to determine its impact on missed injuries, cost, and radiation exposure.

We constructed a decision model comparing two strategies: implementation of the NEXUS Chest CDR vs. usual care in the evaluation of adults with blunt trauma. We derived probabilities, clinical outcomes, effective radiation dose (ERD) from the NEXUS Chest CT validation cohort and costs from the Charge-master at the primary study site. Our primary outcomes were cost and effective radiation dose (ERD) per missed clinically significant injury (CSI).

Using a hypothetical cohort of 1000 adults with blunt chest trauma in each arm, the base case model projected that the implementation of the CDR would result in 161 fewer chest CTs, 0.08 additional missed CSIs, a cost savings of $136,432 and a decrease in 1435 mSv, as compared to Usual Care. To detect one additional CSI, the Usual Care strategy would require 2015 more chest CTs with a cost of $1.8 million and 17,934 mSv more radiation.

Compared to usual care, implementation of the NEXUS Chest CT Major CDR in the evaluation of adults with blunt trauma would greatly reduce CT associated costs and radiation exposure with a slight increased risk of missed CSIs.