Table 1.

Summary of the interventions analyzed.

Intervention	Technology/device	Studya: length/participants/age	Strategies	Study settings/methods	Outcomes: primary/secondary	Measurementsb/Conclusion
Ballantyne et al. [30]	Social network (About my age)/computer	3 months/4/69–85	Internet and computer training	Home/pilot study, prepost interviews	Loneliness	Interview/decreased loneliness
Blažun et al. [32]	E-mail, Internet, and Skype/computer	3 weeks/45/66 in Finland, 77 in Slovenia	Internet and computer training	Home in Finland, residence in Slovenia/prepost test no control; no standard tool for assessment	Loneliness, ICT knowledge, and experience	Questionnaire/decreased loneliness
Cattan et al. [43]	Phone calls/telephone	>3 months/34/55–95	Familiar, simple technology; ensure interactions	Home/mixed methods	Health and wellbeing/loneliness	Questionnaire and interview/decreased feelings of loneliness, increased socialization
Cotten et al. [34]	E-mail, Internet, and Facebook/computer	1–2 weeks/205 (79; 126)/82.8	Internet and computer training	Facility/cross sectional analysis	Loneliness and social isolation/quantity and quality of communications	Hughes 3-items LS (UCLA-based) and questionnaire/decreased loneliness, not social isolation
Dodge et al. [44]	Video chat/touch-screen computer	6 weeks/83 (41; 42)/80.5	Familiar, simple technology; ensure interactions; provide conversation topics	Facility/randomized controlled trial	Cognitive function/loneliness	Hughes 3-items LS (UCLA-based)/no difference
Fokkema and Knipscheer [31]	E-mail and Internet/computer	3 years/26 (12; 14)/66 in intervention, 68 in control	Internet and computer training	Home/interrupted time series, nonequivalent control group prepost test	Loneliness	DeJong 11-items LS and questionnaire/decreased loneliness
Garattini et al. [45]	Broadcast, messages, and calls/touch-screen computer-phone hybrid	10 weeks/19/65–84	Familiar, simple technology; provide conversation topics	Home/mixed methods, exploratory study	Feasibility/social connectedness	DeJong 6-items LS, log, interview, questionnaire/helped social connection and created interactions
Larsson et al. [39]	E-mail, Internet, Skype, and Facebook/computer	3 months/30/61–89	Internet and computer training	Home/randomized crossover study	Loneliness/satisfaction with social contacts online and offline	UCLA LS/decreased loneliness (significant in both groups); satisfaction with social contacts inconclusive
Machesney et al. [40]	Virtual companion/tablet	1 week/13/65–93	Familiar, simple technology; ensure interactions	Home/one group observational study	Loneliness	UCLA LS/decreased loneliness
Széman et al. [41]	E-mail, Internet, Skype, and Facebook/computer	>6 months/15 (program), 25 (pilot)/>75	Internet and computer training	Home/case study	Loneliness	Observation/increased size of social network
White et al. [42]	E-mail, Internet/computer	5 months/93 (48; 45)/71 in interventions, 72 in control	Internet and computer training	Facility/randomized controlled trial	Loneliness	UCLA LS (modified anchors)/decreased loneliness (nonstatistically significant)
Baez et al. [46]	Virtual classroom, messages, and predefined messages/tablet	10 weeks/40 (20; 20)/71.5	Internet and computer training; familiar, simple technology; ensure interactions	Home/randomized pilot trial	Training adherence/loneliness and social wellbeing	Hughes 3-items LS (UCLA-based)/no significant difference
Czaja et al. [35]	E-mail, Internet, virtual classroom, and messages/computer	12 months/300 (150; 150)/76.15	Internet and computer training; familiar, simple technology; provide conversation topics	Home/randomized controlled trial	Loneliness and social isolation/attitude towards technology and proficiency	Hawthorne friendship scale, Cohen perceived social support scale, Lubben social network size, UCLA LS v3/decreased loneliness and social isolation
Banbury et al. [47]	Skype/tablet	44 weeks/52/73.0	Familiar, simple technology; ensure interactions; provide conversation topics	Home/nonrandomized noncontrolled prepost test	Educational goals/social support	Social (egocentric) network analysis interviews, focus groups/increased network size
Barbosa et al. [48]	Messages (video, photos, audio, predefined)/tablet	3 months/12/82.5	Familiar, simple technology; ensure interactions	Facility/feasibility study	Feasibility/social connectedness	Hughes 3-items LS (UCLA-based), Abbrev. Duke social support index/increased social interactions, high perceived social connectedness
Chiu and Wu [33]	Line (messaging service), YouTube/tablet	5 months/54 (19; 18; 17)/73.0	Internet and computer training; provide conversation topics	Facility/group randomized trial	Cognitive, physical functioning and psychological wellbeing/quality of life	CES-D Chinese version, Taiwanese inventory of social supportive behavior/increased social support and satisfaction with contacts
Gutierrez et al. [36]	Video chat, messages, and photos/tablet	9 weeks/9/69–81	Familiar, simple technology; ensure interactions	Home/empirical in-the-wild study	Frequency of social interactions	One-way repeated ANOVA/increased social interactions
Isaacson et al. [49]	Virtual classroom, video chat, photos/TV, remote, and webcam	4-5 weeks/40/85.86	Familiar, simple technology; ensure interactions	Home/pilot study	Technology adoption/emotional wellbeing	UCLA LS v3, Lubben social network scale/decreased loneliness, increased social wellbeing and social network size
Jarvis et al. [37]	WhatsApp (messaging service)/mobile phone (smartphone)	3 months/29 (13; 16)/74.93	Internet and computer training; ensure interactions	Facility/randomized controlled study	Loneliness and social cognition/use of technology	YSQ short form, DeJong 6-items LS/decreased loneliness
Jarvis et al. [38]	WhatsApp (messaging service)/mobile phone (smart phone)	3 months/32 (15; 17)/70.42	Internet and computer training	Facility/experimental randomized comparative study	Loneliness	DeJong 6-items LS, focus groups/decreased loneliness
Morton et al. [50]	E-mail, Internet, Facebook, and Skype	4 months/76 (44; 32)/80.71	Internet and computer training	Some at home, some at facility/randomized 2 × 2 × 2 study	Cognitive and mental health/social network activity and satisfaction, loneliness	Social network activity index, UCLA LS v3/no difference in loneliness, increased social network activity
Myhre et al. [51]	Facebook	8 weeks/41 (14; 13; 14)/80.0 Facebook, 73.38 online diary, 79.29 Waiting list	Internet and computer training; ensure interactions;	Some at home, some at facility/3-arm study	Neuropsychological tests/social engagement	UCLA LS v3, MOS social support survey, Lubben social network 18-i scale/no significant difference
Barbosa et al. [52]	Video chat, photos, audio recording, predefined messages	2 months/5/87.2	Familiar, simple technology	Facility/embedded case study	Feasibility and adoption/social connectedness	Hughes 3-items LS (UCLA-based), Abbrev. Duke social support index/no significant difference
Pauly et al. [53]	E-mail, Internet, social network, and messages	>6 months/92/67.7	Internet and computer training	Home/prepost, repeated measures study	Physical activity/loneliness and executive functioning	Self-reported questionnaires, R-UCLA LS/no significant difference
Tomasino et al. [54]	Virtual classroom and messages	8 weeks/47/69.6	Internet and computer training; ensure interactions; provide conversation topics	Home/pilot study	Depression, tech use and usability/social support and isolation	PROMIS social isolation 6-i, social Provisions scale/no significant difference

^aThe number of participants in controlled studies is shown in parentheses (intervention; control); participants' age is indicated as mean, age range, or as reported in the study. ^bLS stands for Loneliness Scale.