Patient and Public Involvement to Co-Design How We Understand and Communicate Mortality Risk for Patients Aged 90 and Over Considering Elective Total Hip Replacement (THR)

Background: Patient and Public Involvement and Engagement (PPIE) is integral to ensuring health research remains grounded in patient priorities and lived experience. This is especially critical for underrepresented groups, such as adults aged 90 and over considering elective total hip replacement (THR). This demographic experiences a small but meaningful risk of postoperative mortality, yet conventional numeric risk communication often fails to align with their values, communication preferences, and the existential context of very advanced age. Traditional PPIE methods, like focus groups, may inadvertently exclude this group due to sensory, mobility, or digital barriers. Methods: This PPIE activity engaged eight public contributors with a lived experience aged 90–96 years (including their carers) through semi-structured one-to-one telephone conversations, aligned with the GRIPP2 Short Form and UK Standards for Public Involvement. We detail our approach to building rapport and facilitating nuanced conversations remotely, focusing on three domains: research context, communication preferences, and decision-making. Our methodology was designed to prioritise relationship-building and flexibility to overcome barriers to participation. Results: Inductive analysis identified three central themes: 1. A Pragmatic Conceptualisation of Risk: Participants framed mortality risk as an acceptable "chance you take," shaped by life experience and advanced age. 2. Values-Based Decision-Making: Quality of life outcomes: mobility, independence, and maintaining an optimistic outlook were prioritised over longevity alone. 3. The Imperative for Compassionate Communication: Participants emphasised a need for clear, respectful, and multi-modal communication, while explicitly rejecting ageist or overly clinical language. Contributors unanimously affirmed the importance of this topic, feeling that as an underserved community, their perspectives on mortality were both valuable in decision making and long overdue. Limitations : This PPIE activity involved a small number of contributors and used telephone-only engagement. While this ensured accessibility, it may limit transferability to other contexts. Future work should test alternative formats and include larger, more diverse samples to enhance generalisability to the nonagenarian populations. Nonetheless, the rich feedback insights from this unrepresented group provide a valuable foundation for future work Conclusions: The findings challenge the primacy of numerical risk presentation for this demographic, underscoring that communication must prioritise dignity, optimism, and clarity. Crucially, contributors affirmed that discussing mortality is a necessary part of informed consent, countering assumptions that this topic should be avoided. These insights directly inform more sensitive and relevant research design and clinical communication tools, ensuring they are grounded in the values and priorities of the patients they are meant to serve.