Presentation (CTI)

OBJECTIVES: Including caregiver quality adjusted life years (QALYs) in economic evaluations is increasingly common, but the best way to do so remains unclear. While several methods have been used in the literature, each carries trade-offs: some fail to fully capture the caregiver impact, while others are inconsistent with core health economic principles. This study explores the key methodological questions raised by commonly used approaches.
METHODS: We applied six methods identified in prior studies: (1) caregiver utilities (absolute values), (2) caregiver disutilities, (3) decrements from the best health state, (4) increments from the worst health state, (5) decrements or increments from a midpoint health state, and (6) a proportional approach. These were assessed across six intervention scenarios reflecting different combinations of cure, morbidity reduction, and survival benefits.
RESULTS: Results varied widely depending on the scenario and method used, especially in how cured and death health states were handled. For a curative treatment that does not extend survival, approaches (1)-(5) consistently showed positive caregiver QALYs with or without the death state; approach (6) showed a smaller benefit, increasing when death was excluded. Excluding the cured state led to divergent results: approaches (1), (4), and (6) predicted negative impacts; (2) and (3) positive; and (5) no impact. For a treatment that cures and extends survival, approaches (1)-(5) showed consistent positive caregiver QALYs, with approach (6) estimating a smaller benefit. Excluding death still yielded positive results across all methods, with varying magnitude. Excluding the cured state caused inconsistency: approaches (1) and (6) predicted negative impacts; (2) and (3) positive; approaches (4) and (5) varied by death state inclusion.
CONCLUSIONS: To value the impact of new treatments on caregivers, we need robust, consistent methods developed in collaboration with caregivers and stakeholders.