Candidate for the Lee B. Lusted Student Prize Competition
To determine the cost effectiveness of performing CT instead of radiography for screening occult wrist fracture at the time of initial presentation at the emergency department.
Method:
We conducted an analytic decision model to compare the cost-effectiveness of CT over follow-up X-ray in management of acute wrist trauma in emergency room. Using two different clinical scenarios as performing CT after a negative X-ray with clinical findings such as focal tenderness, positive Scaphoid compression test, or immobilizing the wrist and perform series of follow-up X-rays. Outcome was calculated as the gain of quality-adjusted-life (QALY) by following each scenarios and the costs were analyzed from both individual and social prospective. The direct medical costs were estimated from Medicare reimbursement rates for 2012. The costs associated with loss of productivity and absence from work was calculated based on average wages established by U.S. Bureau of Labor Statistics.
One-way sensitivity analysis was performed for all variables over the clinically plausible range to determine stability of the model. Two-way sensitivity analysis was used for the correlated variables.
Result: The base case was considered as an active adult in his productive age with a minimum wage salary reported by US labor statistics for 2013. We ran a Monte Carlo micro-stimulation for 10000 times, considering an unnecessary immobilization rate of 30% for the follow-up strategy. The analysis demonstrated CT has an incremental cost of $1764 for the gain of 1 unit of QALY, while this is $2306 for another strategy. These results were derived when the absence from work in case of unnecessary cast was considered only one week. By increasing the absence from work to 4 weeks, the costs associated with follow up strategy increased to $2917. The threshold analysis indicated that adopting CT strategy in management of occult wrist fracture will not be cost effective if the combination of initial X-ray and clinical findings could reach a sensitivity and specificity of 100% and 90%, respectively. The model was stable to change in clinically plausible range for the other variables.
Conclusion: Management of a negative X-ray with positive clinical findings suggestive of possible carpal bones fracture in the emergency room instead of follow up series X-ray might be cost-effective.