Model-based cost-effectiveness analyses for the treatment of chronic myeloid leukaemia: a review and summary of challenges.

Assessing the economic value of treatments for chronic myeloid leukaemia (CML) is important but poses a number of challenges. This paper reviews economic models of CML treatment to learn lessons from this experience and support ongoing efforts to model CML. A search of databases and submissions to key health technology assessment agencies identified 12 studies that reported 22 models. Common practice included the use of cohort Markov models-most models used health states organised around the key stages in CML: chronic phase, accelerated phase and blast phase-and the use of utility estimates in the literature that correspond with the National Institute for Health and Care Excellence reference case. Two key areas of uncertainty were the extrapolation of survival outcomes beyond the period observed by the trial; and the effectiveness of second-line therapies. Further work is required to overcome these uncertainties in existing models, such as longer-term trial data collection, including trials of second-line therapies; validation of health-related quality-of-life instruments; and the testing of alternative modelling approaches. In the meantime, it is important that the impact of uncertainties is tested through the use of sensitivity and scenario analysis.