Social network intervention for loneliness and social isolation in a community setting: the PALS cluster-RCT.

Background: Loneliness and social isolation are associated with adverse mental and physical health outcomes in adults. However, there is a lack of existing research on effective interventions and the contexts in which these could be implemented.

Primary Objective: To assess the clinical and cost-effectiveness of a social network intervention compared to usual care among at-risk populations.

Design: A pragmatic, community-based, cluster randomised controlled trial with embedded health economic evaluation, process evaluation and qualitative study. Outcome assessments were conducted at baseline and at 3 and 6 months.

Setting: The study was conducted in collaboration with 44 community-based organisations in two regions in England.

Participants: Adults aged ≥ 18 years at risk of loneliness and social isolation.

Intervention: A facilitated social network tool ('project about loneliness and social networks'; PALS) designed to link people to opportunities for social involvement. First, participants map and reflect on personal social networks. Second, identification of local resources based on individual preferences, available support, and health and wellness needs.

Main Outcome Measures: The primary outcome was mental wellness at 6-month follow-up, measured by the Short Form questionnaire-12 items mental health component score (MCS). Secondary outcomes included the Short Form questionnaire-12 items Physical Health subscale, loneliness, social isolation, well-being and collective efficacy. Economic measures assessed the cost-effectiveness of the intervention in terms of costs, quality-adjusted life-years and net monetary benefits.

Results: We recruited 469 adults into the study, with 120 withdrawals (25.6%). The main trial results indicate little to no treatment effect of the intervention on either the primary or secondary outcomes compared to usual care. The within-trial economic evaluation found that PALS was inexpensive to deliver but there was no significant difference in quality-adjusted life-years, measures of well-being capability or costs, and the intervention did not lead to demonstrable cost-effectiveness in terms of net monetary benefits. The process evaluation found PALS to be acceptable to all types of community organisations, but low resource availability and capacity to sustain PALS was found across all community organisational contexts. Qualitative interviews ( = 20) highlighted that participants wanted to engage with meaningful social activities but barriers to doing so were psychological (i.e. confidence and competence) and practical (i.e. transport or cost).

Limitations: The timing of COVID-19 and associated restrictions (approximately splitting trial follow-up into thirds of pre-COVID, during the first lockdown, and following the trial reopening) meant its impact on the trial is difficult to assess. There were high levels of missing data (20-30% for most outcomes at 6 months), though methods to handle missing data did not change the conclusions of the trial.

Conclusions: Our findings do not provide strong evidence of the efficacy of the PALS social network intervention to address the complexities of loneliness and social isolation. Although the intervention was acceptable to participants and community organisations who hold the potential to deliver such an intervention, sustainability would require a networked approach between organisations to mitigate against the challenges found in each organisation.

Future Work: Future interventions for loneliness would likely benefit from utilising a multistep approach providing tailored psychological, relational and social components.

Trial Registration: This trial is registered as Current Controlled Trials ISRCTN19193075.

Funding: This award was funded by the National Institute for Health and Care Research (NIHR) Public Health Research programme (NIHR award ref: 16/08/41) and is published in full in ; Vol. 13, No. 1. See the NIHR Funding and Awards website for further award information.