difficulty in finding participants for the various stages of the study

Background: Optimal medication management is one of the essential preconditions for polymedicated home-dwelling older adults with multiple chronic conditions to remain at home and preserve their quality of life and autonomy. This study aims to explore the feasibility and acceptability of an evidence-based, multi-component, interprofessional intervention programme supported by informal caregivers to decrease medication related problems (MRPs) among polymedicated, home-dwelling older adults with multiple chronic conditions.

Methods: The pragmatic multi-site OptiMed pilot study will use an open-label design, where participants know what they are signing up for and will take place in primary healthcare settings in Portugal and Switzerland. The research population will comprise polymedicated home-dwelling adults aged 65 years old or more, at risk of MRPs and receiving community-based healthcare.

Discussion: This pilot study will focus on the recruitment and collaboration of study participants and piloting the feasibility of the evidence-based, multi-component, interprofessional intervention programme. The full-scale study, following on from the OptiMed pilot study, will support the development of a standardised, evidence-based, multi-component, interprofessional intervention programme to reduce MRPs. It will also be an essential part of follow-up research programmes on the multiple roles of informal caregivers, as it will put their coordination tasks into perspective with their own needs.

The pilot study's primary objective is to explore the feasibility and acceptability of an evidence-based, multi-component, interprofessional intervention programme, supported by informal caregivers, to decrease MRPs among polymedicated, home-dwelling older adults with multiple chronic conditions. The pilot study will gather information about the feasibility and acceptability of recruitment, participant retention, adherence, fidelity, acceptability and satisfaction, intervention dose, and the intervention programme's overall credibility. The secondary objective is to test the different data collection tools planned for use in the full study.

After the older participant has been recruited via their nurse primary-care manager, working for their primary healthcare centre (PHC), the intervention's first component (t0) involves a baseline assessment of them at a meeting conducted by a research nurse. The research is explained to the older participant in detail, both orally and in writing, and the consent form is signed. Following this, the older participant is asked to answer some sociodemographic and health-related questions and provide a complete list of their current medication prescription. The research nurse completes a questionnaire on the risk of MRPs-doMESTIC risk. A first meeting also takes place individually with the family caregiver (who will also answer some sociodemographic and health-related questions and describe their role in medication management). The older participant is asked to identify the healthcare professional(s) (GP or specialist, nurse primary-care manager and/or community pharmacist) most involved in their medication management.

The second component (t1) involves a review of the prescribed medications in week 1, including a medication reconciliation and a structured medication analysis by the pharmacist study partner, to identify drugs with a high risk of MRPs among older adults. This will use the STOPP/START criteria, and undertreated indications or missed therapies will use the START criteria. The older adult's physician will be invited to participate in the review of prescribed medications in collaboration with the pharmacist study partner. They will discuss validated, evidence-based, internationally recognised guidelines to reconsider beneficial or non-beneficial therapies or to simplify and focus on specific care goals and adjust medications to be consistent with guidelines. If the older adult's physician adopts no changes despite the medication review (t1) highlighting their relevance, the research team will inform the older adult of their physician's decision and will invite them to proceed with the study.

Based on the baseline assessment (t0), the research nurse will use a joint consultation in week 2 to explore the needs and care goals of the older participant and their informal caregiver so as to reduce the risk of MRPs (t2). The research nurse will then design a target education plan-in collaboration with the designated healthcare professional(s)-to empower the older adult's medication management and reduce the risk of MRPs (t2). This is based on a four-step patient empowerment process: 1) the patient understands their role; 2) the patient acquires sufficient knowledge to be able to engage with their healthcare professionals; 3) the patient improves their skills; and 4) there is a facilitating environment. Each older adult participant's plan will be unique and consider their preferences, medication literacy and treatment adherence.

During weeks 3 and 4 (t3), the research nurse will help the older participant and their informal caregiver to implement their target education plan (t2) aimed at empowering their medication management and promoting their active engagement in reducing the risks of MRPs. Two joint consultations will be organised between the older adult, their informal caregiver and the research nurse (once each week). During planned home visits, the nurse will periodically evaluate older adults' medication status (primary and secondary outcomes) and promote communication between the different professional and non-professional actors involved in medication management.

The research nurse will carry out a final assessment (t4) of each older adult's risks of MRPs in week 5 (35-40 days after t0) in collaboration with the study partner pharmacist. The occurrence of MRPs and medication-related hospital admissions will be investigated. Finally, the acceptability of the interprofessional intervention programme to reduce MRPs will be assessed by the healthcare professionals designated by the older adult in a final questionnaire.

As already described, the medication-management intervention programme guiding OptiMed's pilot study comprises four components based on concurrent interacting processes previously identified by Boult and Wieland. The pilot study will explore possible biases so that they can be correctly addressed in the full study.

Inclusion Criteria:

• Aged 65 or older for both men and women
• Suffering from multiple chronic conditions (two or more)
• Managing at least four prescribed medications daily for more than 90 days (2) (explored during recruitment)
• At risk of MRPs identified using the doMESTIC RISK tool
• Living alone or with a partner, in a rural or urban area
• Supported by a Primary Healthcare Centre
• An informal caregiver is involved in medication management
• Gives written informed consent

Exclusion Criteria:

• Unable to speak and understand French
• Moderate or severe dementia criteria (≥ 10 on the Six-item Cognitive Impairment Test, 6-CIT)
• No risk of MRPs (doMESTIC RISK tool score < 5)
• No informal caregiver

The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.