OBJECTIVES: coreHEM, a core outcome set (COS) for hemophilia gene therapy (GT) was identified by multi-stakeholder consensus (Iorio, Haemophilia, 2018). When consistently measured, the COS will inform a value-based approach to evaluating GT. First steps to determining appropriate measurements for each outcome were previously reported (ISPOR 2018). One outcome, mental health (MH) outlook, was regarded as highly important to capture the potential transformational impact of GT, however no instruments that measured MH when receiving a novel treatment were identified. Suggestions were for an instrument with a summary score evaluating concepts that contribute to MH along with qualitative data to capture the impact of a potential cure. coreHEM has been mapped to a hemophilia value framework (O’Mahony, Haemophilia, 2018) and while broad overlap was reported, gaps were identified for the MH outlook outcome; the group encouraged prioritization of this outcome for data collection/publication (Skinner, EAHAD, 2022). coreHEM MH is a patient-reported outcome measure (PROM) development project initiated to provide a content-validated instrument that can be used to measure this outcome.

METHODS: A conceptual framework and interview guide for MH outlook in hemophilia were developed from a literature/evidence review. Concept elicitation interviews were used to identify concepts and refine the framework. PROM items were developed from priority concepts.

RESULTS: Thirty-two people with hemophilia (PWH) participated in concept elicitation interviews. The framework includes five domains (anxiety, depression, stigma, life interference, and identity). The PROM is currently undergoing cognitive debriefing (expected n=30 PWH) with a focus on understandability and relevance of items.

CONCLUSION: A content-validated instrument will soon be available for use as an exploratory outcome in hemophilia GT clinical trials and real-world settings. Its use will allow for collection of MH outlook data, meeting the needs of the value framework and helping fulfill the intentions of the COS.