Objectives To identify data availability, gaps, and patterns for population level prevalence of loneliness globally, to summarise prevalence estimates within World Health Organization regions when feasible through meta-analysis, and to examine temporal trends of loneliness in countries where data exist. Design Systematic review and meta-analysis. Data sources Embase, Medline, PsycINFO, and Scopus for peer reviewed literature, and Google Scholar and Open Grey for grey literature, supplemented by backward reference searching (to 1 September 2021) Eligibility criteria for selecting studies Observational studies based on nationally representative samples (n≥292), validated instruments, and prevalence data for 2000-19. Two researchers independently extracted data and assessed the risk of bias using the Joanna Briggs Institute checklist. Random effects meta-analysis was conducted in the subset of studies with relatively homogeneous research methods by measurement instrument, age group, and WHO region. Results Prevalence data were available for 113 countries or territories, according to official WHO nomenclature for regions, from 57 studies. Data were available for adolescents (12-17 years) in 77 countries or territories, young adults (18-29 years) in 30 countries, middle aged adults (30-59 years) in 32 countries, and older adults (≥60 years) in 40 countries. Data for all age groups except adolescents were lacking outside of Europe. Overall, 212 estimates for 106 countries from 24 studies were included in meta-analyses. The pooled prevalence of loneliness for adolescents ranged from 9.2% (95% confidence interval 6.8% to 12.4%) in South-East Asia to 14.4% (12.2% to 17.1%) in the Eastern Mediterranean region. For adults, meta-analysis was conducted for the European region only, and a consistent geographical pattern was shown for all adult age groups. The lowest prevalence of loneliness was consistently observed in northern European countries (2.9%, 1.8% to 4.5% for young adults; 2.7%, 2.4% to 3.0% for middle aged adults; and 5.2%, 4.2% to 6.5% for older adults) and the highest in eastern European countries (7.5%, 5.9% to 9.4% for young adults; 9.6%, 7.7% to 12.0% for middle aged adults; and 21.3%, 18.7% to 24.2% for older adults). Conclusion Problematic levels of loneliness are experienced by a substantial proportion of the population in many countries. The substantial difference in data coverage between high income countries (particularly Europe) and low and middle income countries raised an important equity issue. Evidence on the temporal trends of loneliness is insufficient. The findings of this meta-analysis are limited by data scarcity and methodological heterogeneity. Loneliness should be incorporated into general health surveillance with broader geographical and age coverage, using standardised and validated measurement tools. Systematic review registration PROSPERO CRD42019131448.

No abstract

Objectives Despite media and public dialog portraying loneliness as a worsening problem, little is known about how the prevalence of loneliness has changed over time. Our study aims to identify (a) temporal trends in episodic and sustained loneliness (lonely in 1 wave vs consistently lonely in 3 consecutive waves); (b) trends across sociodemographic subgroups by sex, race/ethnicity, birth cohort, education, employment status, marital status, and living alone; and (c) longitudinal predictors of loneliness in middle-aged and older Americans (≥50 years). Methods Based on Waves 3 (1996) to 14 (2018) of the Health and Retirement Study (n = 18,841–23,227), we conducted a series of lagged mixed-effects Poisson regression models to assess trends of episodic and sustained loneliness in the overall and sociodemographic subgroup samples (by sex, race/ethnicity, birth cohort, education, employment, relationship, and living alone status). To examine the predictors of episodic and sustained loneliness, we used a multivariate mixed-effects Poisson regression model with all sociodemographic variables entered into the same model. Results Episodic loneliness prevalence decreased from 20.1% to 15.5% and sustained loneliness from 4.6% to 3.6%. Trends were similar across most subgroups. Males, Caucasians, those born in 1928–1945, with university education, working, married/partnered, and those not living alone reported lower episodic and sustained loneliness, although associations with sustained loneliness were stronger. Discussion Contrary to common perceptions, loneliness has decreased over 20 years of follow-up in middle-aged and older Americans. Several sociodemographic subgroups have been identified as having a higher risk of loneliness, prompting targeted public health attention.

ImportanceIt has been suggested that interventions that aim to improve social well-being may contribute to decreased health care use; however, such evidence has not been fully systematically synthesized.ObjectiveTo systematically review and meta-analyze available evidence on the associations between psychosocial interventions and health care utilization.Data SourcesMedline, Embase, PsycInfo, Cumulated Index to Nursing and Allied Health Literature, Cochrane, Scopus, Google Scholar, and reference lists of systematic reviews were searched from inception until November 31, 2022.Study SelectionIncluded studies were randomized clinical trials reporting on both health care utilization and social well-being outcomes.Data Extraction and SynthesisThe reporting of the systematic review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline. Full-text and quality assessments were conducted by 2 reviewers independently. Multilevel random-effects meta-analyses were used to synthesize the data. Subgroup analyses were conducted to examine the characteristics associated with decreased health care use.Main Outcomes and MeasuresThe outcome of interest was health care utilization, including primary, emergency, inpatient, and outpatient care services. Social well-being was measured as social support, social participation, social relationships, community support, social integration, or loneliness.ResultsA total of 41 studies were retrieved from 18 969 citations; 37 studies were eligible for meta-analysis. Data were analyzed for 7842 participants, including 2745 older adults, 1579 young women considered to be at risk of social and mental health disadvantages, 1118 people with chronic illnesses, 1597 people with mental illnesses, and 803 caregivers. The odds ratio (OR) random-effects model showed an overall reduction in health care use (OR, 0.75; 95% CI, 0.59 to 0.97), but the standardized mean difference (SMD) random effect model showed no association. An improvement in health care utilization was observed in association with social support interventions (SMD, 0.25; 95% CI, 0.04 to 0.45) but not in loneliness interventions. Subgroup analysis indicated a reduced length of inpatient visits (SMD, −0.35; 95% CI, −0.61 to −0.09) and number of emergency care visits (OR, 0.64; 95% CI, 0.43 to 0.96) following the intervention. However, an increase in outpatient care associated with psychosocial interventions was observed (SMD, 0.34; 95% CI, 0.05 to 0.62). The largest reductions in health care use were associated with interventions among caregivers (OR, 0.23; 95% CI, 0.07 to 0.71) and individuals with mental illnesses (OR, 0.31; 95% CI, 0.13 to 0.74).ConclusionsThese findings suggest that psychosocial interventions were associated with most measures of health care utilization. As the association differed by participant and intervention delivery characteristics, these characteristics should be considered in the design of future interventions.