Background: Older people want to age in place. Despite advancing functional limitations and their desire of aging in place, they are not always faithful to therapy that maintains independence and promotes safety. Occupational therapists can facilitate aging in place. Occupational therapy is defined as the therapeutic use of everyday life occupations with persons, groups, or populations for the purpose of enhancing or enabling participation.

Aim: To describe the content a high-adherence-to-therapy and evidence-based occupational therapy intervention to optimize functional performance and social participation of home-based physically frail older adults and wellbeing of their informal caregiver, and the research activities undertaken to design this intervention.

Methods: A roadmap was created to develop the occupational therapy intervention. This roadmap is based on the Medical Research Council (MRC) framework and is supplemented with elements of the Intervention Mapping approach. The TIDieR checklist is applied to describe the intervention in detail. A systematic review and two qualitative studies substantiated the content of the intervention scientifically.

Results: The application of the first two phases of the MRC framework resulted in the ProMOTE intervention (Promoting Meaningful activities by Occupational Therapy in Elderly). The ProMOTE intervention is a high-adherence-to-therapy occupational therapy intervention that consists of six steps and describes in detail the evidence-based components that are required to obtain an operational intervention for occupational therapy practice.

Conclusion: This study transparently reflects on the process of a high-quality occupational therapy intervention to optimize the functional performance and social participation of the home-based physically frail older adult and describes the ProMOTE intervention in detail. The ProMOTE intervention contributes to safely aging in place and to maintaining social participation. The designed intervention goes beyond a description of the 'what'. The added value lies in the interweaving of the 'why' and 'how'. By describing the 'how', our study makes the concept of 'therapeutic use-of-self' operational throughout the six steps of the occupational therapy intervention. A further rigorous study of the effect of the ProMOTE intervention on adherence, functional performance and social participation is recommended based to facilitate the implementation of this intervention on a national level in Belgium.