Optimising person-centered rehabilitation programmes for older adults with disability across health care systems: A realist review and synthesis

PROSPERO PROTOCOL
Rationale for the review
The rehabilitation needs of older adults are increasingly complex due to rising levels of frailty, multimorbidity, and disability - conditions that often interact and reinforce one another. To address these multifaceted needs, person-centered and coordinated rehabilitation approaches that embrace a biopsychosocial perspective are essential. Although the WHO's International Classification of Functioning, Disability and Health (ICF) provides a framework for such approaches, many Western healthcare systems continue to struggle with fragmented services, poor interprofessional collaboration, and organizational barriers.

Existing research has primarily focused on evaluating outcomes, often overlooking the mechanisms and contextual factors that influence the success or failure of complex rehabilitation programmes. As a result, limited insight exists into how, why, for whom, and under what circumstances person-centered rehabilitation works. A realist review offers a way to unpack the 'black box' of complex interventions by exploring the underlying mechanisms and the specific contextual conditions that enable or hinder their effectiveness.

This review aims to develop a deeper understanding of the effectiveness of person-centered rehabilitation for older adults with disabilities by applying a realist lens. By synthesizing evidence across multiple levels - individual, professional, and systemic - this review seeks to inform the design and implementation of future interventions that are both contextually sensitive and mechanism-informed.

Review objectives
This realist review aims to understand how, why, for whom, and under what circumstances person-centered rehabilitation programmes work (or do not work) for older adults with disabilities leading to complex rehabilitation needs. Specifically, the review seeks to identify:

1. The mechanisms through which person-centered rehabilitation interventions produce intended or unintended outcomes.

2. The contextual factors - at individual, professional, and system levels - that enable or hinder the activation of these mechanisms.

3. The interactions between context and mechanism that shape outcomes in different rehabilitation settings.

The review will focus on rehabilitation programmes delivered across professional and organisational boundaries, with particular attention to person-centeredness, coordination, and biopsychosocial approaches to rehabilitation. The objective is to generate a programme theory that explains how person-centered rehabilitation can best be designed and delivered to improve physical, psychological, and social outcomes for older adults with complex rehabilitation needs.

Ultimately, the review aims to provide decision-makers, service providers, and practitioners with actionable insights into what works, for whom, and why, in order to strengthen the implementation of person-centered rehabilitation in real-world rehabilitation systems.