On-site pharmacist implementation trial in residential aged care homes in urban, regional, rural and remote (OPTIMISER3) Australia: study protocol.

BACKGROUND: Older people living in RACHs experience high rates of medication-related harm, particularly in regional, rural, and remote settings where access to pharmacist-led services is limited. The Aged Care On-site Pharmacist (ACOP) model was introduced nationally in Australia in 2024 to strengthen medication management in residential aged care homes (RACHs). While earlier studies have demonstrated the feasibility and benefits in metropolitan areas, little is known about effective implementation across diverse geographic contexts. The OPTIMISER3 Australia study aims to identify strategies and adaptations to support implementation and scale-up of the ACOP model across diverse geographic settings, and to determine appropriate quality and performance indicators to support its ongoing monitoring and sustainability. METHODS: OPTIMISER3 is a multiphase, mixed-methods implementation study involving eight RACHs across urban, regional, rural, and remote areas in Australia. Phase 1 comprises co-design of locally adapted ACOP service models with staff, residents, families, general practitioners, and pharmacists. Phase 2 involves 12 months of implementation, and Phase 3 evaluates implementation, pharmacist integration, and sustainability using qualitative and quantitative data. Guided by the Consolidated Framework for Implementation Research and Normalisation Process Theory, the study will also examine medication-related quality indicators and pharmacist activity data to identify measures suitable for ongoing monitoring. DISCUSSION: This study will provide real-world evidence to support sustainable implementation of the ACOP model across varied aged care settings. By combining implementation science with co-design, OPTIMISER3 will identify context-specific adaptations and practical quality indicators to guide ongoing national delivery of ACOP services. Findings will support aged care providers, policymakers, and pharmacists in improving medication management in Australian aged care.