Optimising Prescribing in care homes Using pharmacogenomicS: a mixed methods exploratory study (The OPUS Study)

Background Our population is ageing; adults are living longer with increasing multimorbidity, consequent polypharmacy and frailty, placing individuals at risk of adverse drug reactions (ADR) and subsequent hospital admission contributing to compound pressures across the NHS. Care home residents aged 65 years and older are particularly susceptible to ADR. Optimising prescribing in care homes is an NHS priority; pharmacogenomics, the use of genetic information to predict ADR, provides an additional means through which to reduce potentially inappropriate prescribing and thus harm caused by ADRs. Objectives Objectives are: Establishing current prescribing epidemiology in relation to medications with known gene-drug interactions within a care home population, including those with dementia; Understanding practical and ethical components of implementing pharmacogenomics in care homes from the perspectives of older people living in care homes and the community including people with dementia, their families, care home staff, and prescribing clinicians; Developing a network of academics, clinicians, care home staff and members of the public to support OPUS work and co-produce our Programme Grant for Applied Research (PGfAR); Designing a care-pathway prototype, based on the MRC complex intervention framework, to refine, test for feasibility, and trial in our future PGfAR. Development work plan and timeline The Secure Anonymised Information Linkage (SAIL) Databank will be used to describe prescribing epidemiology between 2018-2024 running from 01/06/25-31/05/26, and will link prescribing with hospital admission within the same three month period. The annual denominator population of care home residents will be approximately 15,700. Incidence and prevalence of medications with known drug-gene interactions will be calculated and stratified by deprivation and ethnicity. Qualitative interviews (n~36), running from 01/06/25-31/01/26, will be conducted with older adults living in care homes and the community, their families, care home staff, and prescribing clinicians, ensuring diversity and inclusivity within our sample. Over the 18 months of OPUS, work will continue with our collaborators and the Keele Patient and Public Involvement team, and we will establish relationships with under-heard community groups, to support interpretation of results and co-produce the PGfAR with planned submission in October 2026. Impact Research findings will be standalone outcomes and contribute to the PGfAR. Results will be shared with the public according to preferences expressed during OPUS, and through the national Network of Excellence on Pharmacogenomics and Medicines Optimisation to enable our results to inform other ongoing or planned research. Knowledge of prescribing epidemiology will provide foundations for future research. Understanding likely challenges of pharmacogenomics implementation will enable troubleshooting with our OPUS network to deliver a cost effective PGfAR,optimised for success. OPUS may highlight additional work to incorporate into the PGfAR. Our close working relationships with community groups will encourage engagement in research within communities in under-heard regions. OPUS and the PGfAR will enable our oldest, frailest, members of society, those seldom included in research, to receive equitable care within the NHS using new technologies to reduce the burden of inappropriate prescribing that affects all aspects of health and well-being and thus reduce associated compound pressures across the NHS.