An attribution of value framework for combination treatments.

Objective: The use of cost-effectiveness methods to support policy decisions has become well established but difficulties can arise when evaluating a new treatment which is indicated to be used in combination with an established "backbone treatment." If the latter has been priced close to the decision maker's willingness to pay threshold, this may mean that there is no headroom for the new treatment to demonstrate value, at any price, even if the combination is clinically effective. Without a mechanism for attributing value to component treatments within a combination therapy, the health system risks generating negative funding decisions for combinations of proven clinical benefit to patients. The aim of this work was to define a value attribution methodology which could be used to allocate value between the components of any combination treatment.

Methods: The framework is grounded in the standard decision rules of cost-effectiveness analysis and provides solutions according to key features of the problem: perfect/imperfect information about component treatment monotherapy effects and balanced/unbalanced market power between their manufacturers.

Results: The share of incremental value varies depending on whether there is perfect/imperfect information and balance/imbalance of market power, with some scenarios requiring the manufacturers to negotiate a share of the incremental value within a range defined by the framework.

Conclusions: It is possible to define a framework that is independent of price and focuses on benefits expressed as Quality-Adjusted Life-Year (QALY) gains (and/or QALY equivalents for cost-savings), a standard metric used by many HTA agencies to evaluate novel treatments.