The prevalence of loneliness across 113 countries: systematic review and meta-analysis.

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.

Exercise frequency during the COVID-19 pandemic: A longitudinal probability survey of the US population.

Regular physical activity is important for general health and reduces the risk for COVID-19 infections and for severe outcomes among infected people. However, measures to mitigate COVID-19 likely decrease population physical activity. This study aimed to examine 1) changes in exercise frequency in a representative sample of US adults during the pandemic (04/01/2020-07/21/2021), and 2) how sociodemographic characteristics, pre-COVID health-related behaviors and outcomes, and state-level stringency of COVID-19 containment measures predict exercise frequency. Self-reported exercise frequency and its individual-level predictors were determined based on 151,155 observations from 6,540 adult participants (aged ≥ 18 years) in all US states from the Understanding America Study. State-level stringency of COVID-19 control measures was examined from the Oxford COVID-19 Government Response Tracker. Exercise frequency varied significantly over 28 survey waves across 475 days of follow-up (F 1,473 = 185.5, p < 0.001, η2 = 0.28, 95% CI = 0.23-1.00), where exercise frequency decreased between April 2020 and January 2021, and then increased from January 2021 to July 2021. Those who were younger, living alone, non-White, had no college degree, lower household income, low pre-pandemic physical activity levels, obesity, diabetes, kidney disease and hypertension had lower exercise frequency. State-level stringency of COVID-19 control measures was inversely associated with exercise frequency (B = 0.002, SE = 0.001, p < 0.01) between April and December 2020 when the overall stringency level was relatively high; but the association was non-significant (B = 0.001, SE = 0.001, p > 0.05) between January and July 2021, during which the stringency index sharply declined to a low level. This longitudinal probability survey of the US population revealed significant fluctuations in exercise during COVID-19. Low exercise levels are concerning and deserve public health attention. Health inequalities from physical inactivity are likely to exacerbate because of COVID-19. Physical activity promotion in safe environments is urgently warranted, especially in at-risk population subgroups.