Potential Solutions for the Cost-Effectiveness Paradox of Improving Carer Quality-of-Life in Terminal Conditions

OBJECTIVES: Published systematic reviews have identified very limited application of carer quality-of-life (QoL) within cost-utility analyses (CUA) for terminal conditions. This is expected given the findings of a previous review of the application of carer QoL in NICE appraisal, where in all cases, carer QoL was applied as disutilities. Despite treatments providing a benefit for patients, application of carer disutility in terminal conditions paradoxically results in reduced cost-effectiveness, driven by the removal of carer disutility when the patient has passed. In the absence of comprehensive research determining the impact of bereavement on carer QoL. This study considers potential methods to allow this missed impact on carer QoL in terminal conditions to be incorporated in CUAs.

METHODS: Four methods were hypothesised; I: utility increment (Heath state (HS)1 carer increment = HS2 carer disutility – HS1 care disutility, death HS carer=0 i.e. benefit to the carer of maintaining a patient within that state; II: average of the patient and carer utility within each HS, death HS carer=0. The latter two methods were explored to understand the impact of bereavement assumptions; III: patient and carer utilities are combined (QALYs/year=2), death HS carer=0; IV: method III with death HS carer= age-adjusted utility. These methods were compared to the standard disutility approach within a three-health state partitioned survival model.

RESULTS: Applying a decrement consistently increased the ICER to vary degrees across scenarios. Method I resulted in consistently lower ICERs, whereas, Method II had a slightly decreased ICERs with most scenarios but a few with marginally higher ICERs. Methods III and IV had significant decreases and increases in the ICERs, respectively.

CONCLUSIONS: The range of ICERs with methods III/IV demonstrate the importance of understanding the impact of bereavement on carer QoL. However, Method I may provide an estimate of the additional value of carer impact for payer deliberation today.