COST-EFFECTIVENESS OF THE USE OF CT IN MINOR HEAD INJURY

Purpose

Prediction rules can be used to select patients for CT after minor head injury (MHI). We assessed the cost-effectiveness of selective CT strategies, compared with CT in all patients.

Methods

We evaluated 5 strategies: CT in all MHI patients; selective CT according to the New Orleans Criteria (NOC), Canadian CT Head Rule (CCHR) or CT in Head Injury Patients (CHIP) rule; and no CT (reference strategy). We used a decision tree for the short-term, and a Markov model for the long-term costs and effectiveness. Outcome measures were first year and lifetime costs, quality adjusted life years (QALYs), and the incremental cost-effectiveness ratio (ICER). The model’s robustness was tested against varying the model parameters across their 95% confidence intervals in n-way and probabilistic sensitivity analysis and value of information (VOI) analysis was performed.

Results

Selective CT according to the CCHR or CHIP rule could lead to substantial US cost-savings (US$ 120 million respectively US$ 71 million). At prediction rules’ sensitivities below 97% to identify patients requiring neurosurgery, CT in all patients was cost-effective. Sensitivity analyses demonstrated that the CHIP rule was most likely to be cost-effective. VOI analysis demonstrated an expected value of perfect information of US$ 7 billion, mainly due to uncertainty in long-term functional outcome.

Conclusions

Selecting MHI patients for CT is cost-effective, provided that the sensitivity to identify patients requiring neurosurgery is extremely high. More research is needed to increase certainty on long-term functional outcome after MHI. Until such time, CT in all patients is also justified.