**Background:** Social isolation and loneliness in older adults are associated with adverse health outcomes including depressive symptomatology, cognitive and functional decline, cardiovascular disease, and increased mortality risk. The relationship between social isolation and mortality has been compared in magnitude to traditional risk factors such as smoking and high blood pressure. Social prescription programs that link primary care patients to nonmedical community resources offer a promising solution, but their success depends on integrating patient needs with local resources, which could be accelerated by digital tools using ontological technologies.
**Methods:** A meta-review was conducted following PRISMA guidelines using a search strategy combining terms related to older adult population, social isolation and loneliness, and review-type studies across five databases: MEDLINE, Embase, PsycINFO, Social Work Abstracts, and CINAHL. Reviews were excluded if they did not clearly report on interventions directly related to social isolation or loneliness, focused on institutional settings only or caregivers, did not use a systematic search strategy, were not focused on older adults (aged ≥50 years), did not include full study results, were not published in French or English, or were published more than 20 years before extraction (July 2020). Screening was performed in two steps by two reviewers. Data extraction included intervention characteristics, outcomes, and effectiveness (categorized as consistent, mixed, or not supported). Intervention terms were extracted from the literature and compared with terms from community service directories in Montréal, Canada, including 211 Grand Montréal, Données Montréal, Centraide of Greater Montréal, Contactivity Centre, AMI-Québec, FADOQ, and RIAQ.
**Key Results:** From 3801 identified reviews, 2157 were screened after deduplication, 343 full-text reviews were assessed, and 50 met eligibility criteria. Eleven intervention categories were identified across four themes: (1) increasing social interactions (social technology, intergenerational interventions, conducive communities), (2) promoting mental and physical well-being (nonhuman companions, recreational activities, psychological therapy, physical activities), (3) providing instrumental support (occupational therapy/rehabilitation, assistive technology), and (4) providing home and community care (home-based health services, telehealth). Interventions under the themes of increasing social interactions and promoting mental and physical well-being were most effective for social outcomes. Intergenerational interventions and conducive communities presented >70% consistent or mixed effectiveness for reducing loneliness and increasing social networks. Psychological therapy and recreational activities demonstrated >60% consistent or mixed effectiveness for mental health outcomes. Nonhuman companions and telehealth were >60% effective for improving mental health outcomes. When comparing terms from literature versus community data sources, overlap was strongest for psychological therapy, recreational activities, and telehealth (≥30% overlap). However, terms related to physical activity, occupational therapy, assistive technologies, nonhuman companions, and social technology were underrepresented in community databases. An average of 28 (SD 13.4) terms per intervention category were identified from the literature.
**Clinical Implications:** The findings support developing a standardized social prescription ontology to bridge the gap between evidence-based interventions and available community services. A shared nomenclature would help identify service gaps, track intervention effectiveness, and support the work of link workers in social prescription programs. Digital tools incorporating such ontologies could enable personalized matching of patient needs with locally available resources, potentially improving social health outcomes while reducing strain on healthcare systems. The study emphasizes that interventions are more successful when participants take meaningful roles within groups, when a collective purpose is evident, when participants experience autonomy, and when interventions incorporate educational components and multiple strategies. Given the diversity of older adult populations, tailored approaches are likely more successful than one-size-fits-all solutions.