Development of the coreHEM mental health patient‐reported outcome measure – A novel mental health outlook measure for people with haemophilia

INTRODUCTION: Currently, no quality-of-life instrument exists that captures the full experience of the mental health outlook (MHO), a coreHEM core outcome, in people with haemophilia, including the potential transformational experience of receiving gene therapy. AIM: To describe the methods used to develop a content validated patient-reported outcome measure (PROM) that measures MHO for people with haemophilia. METHODS: A conceptual framework, developed from a literature/evidence review, was used to create an interview guide and draft a questionnaire. Males aged 15 or older with severe/moderate haemophilia were eligible to participate in concept elicitation or cognitive debriefing interviews. The conceptual framework was refined based on a thematic analysis of concept elicitation interviews and PROM items were developed from the conceptual framework. Cognitive debriefing sessions that prioritised relevance and understanding of the PROM were held in two rounds; items were updated iteratively. RESULTS: A conceptual framework with five domains (stigma, anxiety, depression, life interference and identity) was constructed from over 300 identified MHO concepts. Fifty-three participants took part in interviews. After 32 concept elicitation interviews, the framework was updated by including eight new sub-concepts and eliminating two. Updates to the questionnaire included items added or removed and improved wording. The final coreHEM MHO PROM has 26 questions in two sections (general mental health associated with haemophilia, and a gene therapy section). CONCLUSIONS: The instrument is content-validated and can be used as an exploratory outcome. MHO scores can be measured and compared to give more insight into patient quality of life.