y Social connection is an umbrella term that encompasses how individuals relate to and interact with one another. As established by the WHO Commission on Social Connection (35), it encompasses structural (e.g. number and variety of relationships, roles and interactions) and functional aspects (e.g. received and perceived support) and the quality (e.g. positive and negative aspects of relationships and interactions) of those connections (35,44). x Social isolation and loneliness are two types of social disconnection. Social isolation refers to the objective state of having limited social interactions or relationships, whereas loneliness reflects a subjective discrepancy between the desired and actual social connections (35). x In contrast, social activity – also referred to as social participation or social engagement – is a vital component of successful ageing (35). It includes activities such as meeting friends, volunteering and and attending social events. y In the studies reviewed, social activity interventions included interventions that incorporate social interaction components involving communication or interaction with others (e.g. group recreational activities, volunteering, attending sporting events or online social interactions). There was a considerable variability in how social activity was defined and measured across studies. Indicators included the frequency of interpersonal contact, size of social networks, level of community participation, or subjective feelings of loneliness and emotional support. This variability in operational definitions presents challenges in synthesizing the evidence and standardizing intervention approaches. y Social engagement was also measured differently across studies. Commonly, it was measured using index scores (e.g. regarding participation in social activities), in which the highest category was compared with the reference category. y WHO’s evidence and gap map of digital (45) and in-person (46) interventions intended to reduce social isolation or loneliness provide examples of available interventions to support social connection throughout the life course. y WHO is currently in the process of developing guidelines for interventions to reduce social isolation and loneliness, from children to older people Programmes to enhance social engagement should be culturally appropriate, inclusive and tailored to the needs and preferences of diverse populations, including older adults and those living in rural or underserved areas. y Practical approaches include strengthening social infrastructure, intergenerational initiatives, peer support networks and digital platforms that facilitate social interaction. y Implementation should address key barriers such as limited mobility, transportation challenges, stigma, caregiving responsibilities and digital exclusion, particularly in older age groups. Additionally, culturally adaptability should be carefully considered because programmes developed in one setting may not translate effectively across diverse cultural norms, social structures and expectations for participation. y Differences between digital and in-person programmes should be considered. Although virtual programmes may reduce barriers to access, they may not fully replicate the social, emotional and cognitive benefits associated with face-to-face interactions. y Social engagement strategies can be effectively integrated into other health promotion and dementia prevention programmes, including those focused on physical activity, nutrition or mental well-being. y Primary care can play an important role in implementation through social prescribing – connecting individuals to community-based social activities and supports that align with their preferences, needs and local availability. y Public awareness campaigns, clinician engagement and multisectoral collaboration (across health, social care, education and community development sectors) are essential to promote participation and scale up sustainable interventions.

Social participation is strongly connected to good health and well-being throughout life, and should be supported over the life course, in line with WHO guidance. Clinical practice: y No dedicated WHO clinical guideline Service delivery and care pathways: y Integrated care for older people (ICOPE): guidance for personcentred assessment and pathways in primary care, 2nd ed (4) Public health and policy: y From loneliness to social connection: charting a path to healthier societies: report of the WHO Commission on Social Connection (6) y Social isolation and loneliness among older people: advocacy brief (7)