Abstract
Social isolation and loneliness are key social determinants of health linked to poor outcomes. While telephone-based support programs have some evidence, their implementation remains understudied. We evaluated the Friendship Line, a 24-h telephone-based support program for older adults, using an implementation science lens. This included structured questionnaires and semi-structured interviews with staff (N = 13), volunteers (N = 17), and older adult callers (N = 27), totaling 57 participants. Qualitative data were analyzed thematically and mapped onto the Consolidated Framework for Implementation Research. Six key features were identified for the success of telephone-based loneliness support programs: (1) fostering trust and reliability through 24-h access; (2) creating a safe and nonjudgmental space; (3) ensuring consistency and relationship building; (4) balancing stability and adaptability during changes; (5) securing ongoing funding; and (6) providing specialized training focused on loneliness and aging. These programmatic features contributed to caller satisfaction, reduced loneliness, and improved connectedness. Effective and sustainable telephone-support lines addressing social isolation and loneliness require multifactorial strategies, including skill development, robust organizational infrastructure, and tailored training to meet the diverse needs of callers.