Cost effectiveness of treatment for amblyopia: an analysis based on a probabilistic Markov model

Aims: To estimate the long term cost effectiveness of treatment for amblyopia in 3 year old children. Methods: A cost utility analysis was performed using decision analysis including a Markov state transition model. Incremental costs and effects during the children’s remaining lifetime were estimated. The model took into account the costs and success rate of treatment as well as effects of unilateral and bilateral visual impairment caused by amblyopia and other eye diseases coming along later in life on quality of life (utility). Model parameter values were obtained from the literature, and from a survey of experts. For the utility of unilateral visual impairment a base value of 0.96 was assumed. Costs were estimated from a third party payer perspective for the year 2002 in Germany. Costs and effects were discounted at 3%. Uncertainty was assessed by univariate and probabilistic sensitivity analysis (Monte-Carlo simulation). Results: The incremental cost effectiveness ratio (ICER) of treatment was €2369 per quality adjusted life year (QALY). In univariate sensitivity analysis the ICER was most sensitive to uncertainty concerning the utility of unilateral visual impairment—for example, if this utility was 0.99, the ICER would be €9148/QALY. Monte-Carlo simulation yielded a 95% uncertainty interval for the ICER of €710/QALY to €38 696/QALY; the probability of an ICER smaller than €20 000/QALY was 95%. Conclusion: Treatment for amblyopia is likely to be very cost effective. Much of the uncertainty in results comes from the uncertainty regarding the effect of amblyopia on quality of life. In order to reduce this uncertainty the impact of amblyopia on utility should be investigated.