Cost-effectiveness of 4 mg dibotermin alfa/absorbable collagen sponge versus iliac crest bone graft for lumbar degenerative disc disease in the United Kingdom

Aims To develop a model to evaluate the cost-effectiveness of 4 mg dibotermin alfa/absorbable collagen sponge (ACS) versus iliac crest bone graft (ICBG) in patients with lumbar degenerative disc disease in the United Kingdom. Materials & methods A Markov decision-analytic model was constructed to calculate costs and quality-adjusted life-years over a 4-year time horizon in each treatment group, from a United Kingdom National Health Service perspective. An individual patient data meta-analysis was undertaken to synthesize data from four randomized controlled trials and two single-arm studies concerning health-related quality of life and procedural resource use. Current cost data from the United Kingdom were then applied to determine the overall mean cost per patient in each group. One-way and probabilistic sensitivity analyses were undertaken to explore the impact of parameter uncertainty. Results The model predicted 4-year discounted cost savings of 192 pound per patient treated with dibotermin alfa/ACS, compared with ICBG, and a gain of 0.0114 QALYs per patient over the same time period. Sensitivity analyses indicated that the results were most sensitive to variability in the differences in health-related quality of life and secondary surgery rate, with dibotermin alfa/ACS having a 60% probability of being cost-effective at a willingness-to-pay threshold of 20,000 pound per QALY gained. Limitations There is uncertainty in the difference in cost and QALYs between the two groups. However, comprehensive sensitivity analyses were undertaken to explore this and present the results in a transparent manner. Conclusions Our results provide an economic case for the use of 4 mg dibotermin alfa/ACS versus iliac crest bone graft, with additional health benefits predicted at reduced overall cost.