Cervical plain films should be eliminated in the high risk patient: Results from decision analysis using an institutional cost perspective

Abstract

Abstract Introduction: In the evaluation of the cervical spine, Helical CT scan has higher sensitivity and specificity than plain radiographs in the high-risk trauma population but is more costly. We hypothesized that institutional indemnity payments associated with missed injuries make helical CT scan the least-costly approach. Methods: A decision analytic model was created for helical CT scan vs. radiographic evaluation of the c-spine. Model variables obtained from the literature: probability of c-spine fracture (11–11.5%), probability of paralysis after missed injury (1.0–10.5%), sensitivity of plain films (44–84%), specificity of plain films (72–89%), sensitivity of CT scan (95–97%), specificity of CT scan (93–100%). Costs from Level 1 trauma center: helical CT scan ($329), plain radiography ($120), missed injuries resulting in paralysis ($500k-$1M). Sensitivity analysis tested model strength, accounted for parameter variability, and determined threshold values for individual parameters. Results: Evaluation of c-spine with helical CT scan has expected cost of $444 compared to $1155 for plain films. CT scan is the least costly alternative if threshold values exceed: $113,616 for indemnity payments, 2.6 % for probability of c-spine fracture, and 1.1% for probability of paralysis. Plain films are a cost-effective alternative if institutional costs of CT scan exceed $1040 or the sensitivity of plain films is greater than 90%. Conclusions: Decision analysis from an institutional perspective shows an economic advantage for helical CT scan. This combined with CT scan’s enhanced sensitivity and specificity suggests that plain film evaluation of the c-spine should be eliminated in the high risk trauma patient.