Estimating the societal impact of medical interventions: a case study in metastatic breast cancer

Aim: Additional value elements like productivity are currently rarely included in economic evaluations since quantitative assessment may be complex or lack clear guidance. In this study we present a practical framework for estimating the societal impact of medical interventions by incorporating additional value elements into economic evaluations. Materials & methods: We applied this framework in the case of trastuzumab deruxtecan (T-DXd) for patients with metastatic breast cancer in five European countries (EU5). In this study we considered the following elements: productivity losses in paid and unpaid work, quality-adjusted life years (QALYs) valued at willingness-to-pay thresholds, the impact on childcare responsibilities, costs associated with formal caregivers, the effect on informal caregivers and impact on governmental accounts including tax revenue, pension and disability benefits. Results: Our findings indicated that some of the value elements included may lead to a positive societal value for the intervention, while others may result in additional costs. Positive impacts were seen in gains to patient productivity (€589 million), QALYs (€1.7 billion), unpaid work (€259 million), childcare responsibilities (€5 million) and tax revenue (€165 million). Conversely, our findings highlighted a greater demand for formal and informal care (-€29 million and -€7 million, respectively) and increased public spending on disability benefits (-€380 million) and pensions (-€44 million) attributed to T-DXd. The main causes of increased costs were the improvement in progression-free and overall survival achieved with T-DXd. Conclusion: Overall, this framework aims to quantify the societal value of new healthcare interventions. This metastatic breast cancer case study illustrates how key value elements can be integrated into economic evaluations, beyond the classical cost–effectiveness analysis, to further support reimbursement decisions.