Objective: To evaluate cost-effectiveness of ring wound protector (RWP) used in open appendectomy.

Materials and Methods: The present study was a decision-tree-based analysis. Model inputs, including costs, utilities, and probabilities of surgical site infection (SSI), were retrieved from the previous studies. The incremental cost-effectiveness ratio (ICER) represented the cost of one additional quality-adjusted life day (QALD). This ratio was calculated by dividing the incremental cost [Thai Baht (THB)] by the incremental QALD. One-way sensitivity analyses were performed by varying each input parameter to see how ICER change. Monte-Carlo simulation with 5,000 replications was used to estimate probabilistic ICER and construct the acceptability curve, demonstrating how the probability of being cost-effective changed

when the willingness-to-pay (WTP) threshold was shifted.

Results: The deterministic ICER of 64,630.78 THB/QALD did not favor RWP use compared with the WTP threshold of 10,000 THB/QALD. However, if the threshold was shifted to 100,000 THB/QALD, it would yield approximately 75% probability of being cost-effective from RWP. Threshold analysis indicated that RWP should cost 281, 301, and 661 THB to be cost-effective at the threshold of 500, 1,000, and 10,000 THB/QALD, respectively.

Conclusion: Routine RWP use might not be cost-effective when QALD is the outcome of interest. Based on the results from the present study, policy-makers could be informed that the adoption of this health technology might not be suitable.