Table 3.

Primary care-based loneliness and social isolation intervention pathways

Referral pathways	Non-referral pathways
Primary care professionals refer older adults to a proxy worker, which connect them to non-healthcare sectors.36 38 64 71 73	External agency recruited older adults from primary care settings, and paired them with volunteers.56
Primary care professionals refer older adults directly to non-healthcare sectors.32 38 55 60 61 65 66 70 74 75	Teams of community health and social care professionals connect hospital discharged adults to volunteers.78
Primary care professionals refer older adults to an external organisation which connect them to non-healthcare sectors.31 62 68	External researchers identify lonely older adults and connect them with primary care services that lead the interventions.58 79
Primary care professionals refer older adults to other healthcare services.34 64 76	No-network interventions, where primary care professionals identified lonely, isolated older adults and delivered the intervention in the same setting.26 57 59 63 69 77