Summary of studies, demographics, measures and outcomes
| Study (year)/country | Population | Sample size | Depression measure | Loneliness measures | Quality-of-life measure | Social support measure | Well-being measure | Other measures | Study quality | Time point | Study outcomes |
| Charlesworth14 (2008)/UK | Carers in dementia | 236 | HADS | Own scale | EQ-5D | MSPSS | – | Anxiety (HADS), social network (PANT), clinical symptoms (PNAS) | High | 6 months 15 months 24 months | No effect |
| Coe25 (2013)/UK | Women with perinatal anxiety and depression | 189 | HADS | – | – | MSSI | – | Anxiety (HADS), relationship (MORS) | Low | 12 months | Effect for anxiety, depression, relationship, social support |
| Davidson 15 (2004)/USA | Individuals with severe mental illness | 260 | CES-D* | – | – | – | WBS | Non-psychotic psychiatric symptomatology (GHQ), social functioning (SFS), psychiatric symptoms (BPRS), functional impairment (GAF-M), diagnosis (SCID), satisfaction (own scale), self-esteem (RSE) | Medium | 4 months 9 months | No effect |
| Harris16 (1999)/UK | Women with chronic depression | 86 | PSE-10 | – | – | – | – | – | High | 13 months | Effect for depression |
| Heller17 (1991)/UK | Isolated elderly women with low support | 265 | CES-D | Own scale† | – | PSS† | PGC | Physical health, ADL, social network (NES), stressful events, social competence (own measure) | Low | 20 weeks | No effect |
| Hughes26 (1999)/UK | Individuals with learning disabilities | 4 | – | – | – | – | – | Social network* (network size), social activities (frequency) | Low | 4 months | No effect |
| MacIntyre18 (1999)/Canada | Elderly individuals | 22 | – | – | – | PRQ* | – | Functional ability (ECOG), health perception (HPQ) | Low | 12 weeks | Effect for social support and well-being |
| McCorkle27 (2008)/USA | Individuals with severe mental illness | 154 | – | – | – | Composite measures of ISEL and LQoL* | Composite measures of RSE, RAS, HHS, MDES, LRI, LQoL | Psychiatric symptoms (HSC, CSI) | High | 6 months 12 months | Effect for social support |
| McNeil19 (1991)/Canada | Depressed elderly individuals | 30 | BDI | – | – | – | – | Aerobic capacity (Cooper Test) | Medium | 6 weeks | Effect for depression |
| Mountain20 (2014)/UK | Socially isolated elderly individuals | 248 | PHQ-9 | DJG | EQ-5D ONS | – | ONS | Mental well-being (SF-36*), self-efficacy (GSE) | High | 6 months | No effect |
| Rantanen21 (2015)/Finland | Elderly individuals with mobility limitations | 121 | – | – | WHO QOL-BREF* | – | WHO QOL-BREF | Physical capacity, social relationship, lower extremity (WHO QOL-BREF, SPPB) | High | 3 months | Effect for physical capacity |
| Sheridan22 (2015)/Ireland | Individuals with severe mental illness | 107 | BDI | SELSA-S | – | – | – | Social functioning (SFS*), support networks (PANT), self-esteem (RSE) | Medium | 3 months 9 months | No effect |
| Walshe24 (2016)/UK | Older adults receiving end-of-life care services | 179 | DJG | WHO QOL-BREF* | mMOS-SS | Social network size, carer burden (CBS-EOLC) and contact with health and social care services | High | 4 weeks 8 weeks | No effect | ||
| White23 (2012)/Australia | Individuals with colorectal cancer | 510 | HADS | – | – | – | – | Anxiety (HADS), care needs (SCNS), colorectal symptoms (own measure), use of health services (frequency) | High | 3 months 6 months 9 months | No effect |
*Primary outcome reported as a patient-reported outcome measure.
† Scale developed by Paloutzian and Ellison32.
ADL, Activities of Daily Living Scale; BDI, Beck Depression Index; BPRS, Brief Psychiatric Rating Scale; CBS-EOLC, Caregiver’s Burden Scale in End-of-Life Care; CES-D, Center for Epidemiological Studies Depression Scale; CSI, Colorado Symptom Index; DJG, De Jong Gierveld Loneliness Scale; ECOG, Performance Status Scale; EQ-5D, EuroQol-5D; GAF-M, Global Assessment of Functioning-Modified; GHQ, Global Health Questionnaire; GSE, General Perceived Self Efficacy; HADS, Hamilton for Anxiety and Depression Scale; HHS, Herth Hope Scale; HPQ, Health Perceptions Questionnaire; HSC, Hopkins Symptom Checklist; ISEL, Interpersonal Support Evaluation List; LQoL, Lehman Brief Quality of Life Interview; LRI, Life Regard Index; MDES, Making Decisions Empowerment Scale; mMOS-SS, modified Medical Outcomes Study Social Support Survey; MORS, Mothers Object Relationship Scale; MSPSS, Multidimensional Scale of Perceived Social Support; MSSI, Maternal Social Support Index; NES, Network Embeddedness Scale; ONS, Office for National Statistics Well-being Scale; PANT, Practitioner Assessment of Network Type; PGC, Philadelphia Geriatric Centre Morale Scale; PHQ-9, Patient Health Questionnaire; PNAS, Positive and Negative Affect Schedule; PRQ Personal Resource Questionnaire; PSE-10, Present State Examination; PSS, Perceived Social Support Scale; RAS, Recovery Assessment Scale; RSE, Rosenberg Self-Esteem Scale; SCID, Structured Clinical Interview for DSM-IV; SCNS, Supportive Care Needs Survey; SELSA-S, Social and Emotional Loneliness Scale for Adults; SF-36, Short Form Health Instrument; SFS, Social Functioning Scale; SPPB, Short Physical Performance Battery; WBS, Wellbeing Scale; WHO QOL-BREF, WHO Quality of Life Short Version Scale.