Barriers and Facilitators to Participation in Physical Activity Programmes for Socially Isolated Older Adults: A Qualitative Systematic Review Protocol

BackgroundSocial isolation among older adults represents a significant public health challenge associated with reduced physical activity, functional decline, and increased mortality. Physical activity programmes offer potential interventions to address both isolation and physical deconditioning, yet participation rates remain suboptimal, particularly among socially isolated older adults who may face unique barriers to engagement. ObjectiveTo systematically identify, appraise, and synthesize qualitative evidence on barriers and facilitators to participation in physical activity programmes among socially isolated older adults, examining experiences, perceptions, and contextual factors that influence engagement across diverse settings and programme types. MethodsThis qualitative systematic review protocol follows the Enhancing Transparency in Reporting the Synthesis of Qualitative Research (ENTREQ) guidelines and PRISMA-P framework. Comprehensive searches will be conducted in MEDLINE, CINAHL, PsycINFO, Scopus, Web of Science, Embase, and AgeLine from inception to December 2025, without language restrictions. Grey literature will be searched through ProQuest Dissertations, OpenGrey, and relevant organizational websites. Two independent reviewers will screen studies using Covidence software, with eligibility criteria including qualitative or mixed-methods studies exploring participation experiences of socially isolated adults aged 60 and above in physical activity programmes. Quality assessment will employ the Critical Appraisal Skills Programme (CASP) Qualitative Checklist. Data SynthesisThematic synthesis will be conducted following Thomas and Hardens approach, involving line-by-line coding, development of descriptive themes, and generation of analytical themes. The Theoretical Domains Framework (TDF) will guide organization of barriers and facilitators across fourteen domains of behavior change. Confidence in review findings will be assessed using GRADE-CERQual. Expected OutcomesComprehensive taxonomy of multi-level barriers and facilitators, development of a conceptual model linking social isolation to physical activity participation, identification of intervention components addressing specific barriers, and evidence-based recommendations for programme design and implementation strategies tailored to socially isolated older adults.