Limb lengthening in achondroplasia: a cost-effectiveness analysis using a Markov model

BACKGROUND: Disproportionate short stature is one of the most characteristic clinical traits of achondroplasia, a condition with a significant impact on patients' autonomy that results in a series of limitations leading to poorer health-related quality of life. Limb lengthening surgery is an effective therapeutic alternative for increasing the stature of persons with achondroplasia. The purpose of this study was to evaluate the cost-effectiveness of bone lengthening in patients with achondroplasia and to estimate the economic impact of the procedure on the Spanish health system by means of a Markov model. RESULTS: Patients with achondroplasia who undergo a limb lengthening procedure gain, on average, 5.954 quality-adjusted life years (QALYs) more than unoperated patients (27.197 vs. 21.243 QALYs). As the procedure entails a mean incremental cost of €49,480, the resulting incremental cost-effectiveness ratio (ICER) is €8,310/QALY. The probabilistic sensitivity analysis (PSA) performed yielded a mean quality of life gain of 6.287 QALYs and a mean cost increase of €49,131, which translates into an ICER of €7,814/QALY. The budget impact analysis was based on the hypothesis that all patients with achondroplasia born every year in the country used as a reference (Spain, n = 15) undergo the procedure. Under this assumption, a cumulative cost increase of €8,896,196 can be estimated over a 15-year period (€8,836,931 following the PSA). CONCLUSIONS: Limb lengthening surgery in patients with achondroplasia can be considered a cost-effective intervention according to the most commonly accepted willingness-to-pay thresholds in Spain and other Western countries.