The COVID-19 pandemic and measures aimed at its mitigation, such as physical distancing, have been discussed as risk factors for loneliness, which increases the risk of premature mortality and mental and physical health conditions. To ascertain whether loneliness has increased since the start of the pandemic, this study aimed to narratively and statistically synthesize relevant high-quality primary studies. This systematic review with meta-analysis was registered at PROSPERO (ID CRD42021246771). Searched databases were PubMed, PsycINFO, Cochrane Library/Central Register of Controlled Trials/EMBASE/CINAHL, Web of Science, the World Health Organization (WHO) COVID-19 database, supplemented by Google Scholar and citation searching (cutoff date of the systematic search December 5, 2021). Summary data from prospective research including loneliness assessments before and during the pandemic were extracted. Of 6,850 retrieved records, 34 studies (23 longitudinal, 9 pseudolongitudinal, 2 reporting both designs) on 215,026 participants were included. Risk of bias (RoB) was estimated using the risk of bias in non-randomised studies—of interventions (ROBINS-I) tool. Standardized mean differences (SMD, Hedges’ g) for continuous loneliness values and logOR for loneliness prevalence rates were calculated as pooled effect size estimators in random-effects meta-analyses. Pooling studies with longitudinal designs only (overall N = 45,734), loneliness scores (19 studies, SMD = 0.27 [95% confidence interval = 0.14–0.40], Z = 4.02, p < .001, I 2 = 98%) and prevalence rates (8 studies, logOR = 0.33 [0.04–0.62], Z = 2.25, p = .02, I 2 = 96%) increased relative to prepandemic times with small effect sizes. Results were robust with respect to studies’ overall RoB, pseudolongitudinal designs, timing of prepandemic assessments, and clinical populations. The heterogeneity of effects indicates a need to further investigate risk and protective factors as the pandemic progresses to inform targeted interventions.

中文翻译：

---

COVID-19 大流行之前和期间的孤独感：荟萃分析的系统回顾。

COVID-19 大流行以及旨在缓解疫情的措施（例如保持身体距离）已被视为孤独的危险因素，孤独会增加过早死亡以及精神和身体健康状况的风险。为了确定自大流行开始以来孤独感是否有所增加，本研究旨在以叙述和统计方式综合相关的高质量初步研究。这项荟萃分析系统评价已在 PROSPERO 注册（ID CRD42021246771）。检索的数据库包括 PubMed、PsycINFO、Cochrane Library/Central Register of Controlled Trials/EMBASE/CINAHL、Web of Science、世界卫生组织 (WHO) COVID-19 数据库，并辅以 Google Scholar 和引文检索（系统检索的截止日期） 2021 年 12 月 5 日）。提取了前瞻性研究的摘要数据，包括大流行之前和期间的孤独评估。在 6,850 条检索记录中，纳入了针对 215,026 名参与者的 34 项研究（23 项纵向研究、9 项伪纵向研究、2 项报告两种设计）。使用非随机研究中的偏倚风险干预措施 (ROBINS-I) 工具估计偏倚风险 (RoB)。连续孤独值的标准化平均差（SMD、Hedges' g）和孤独患病率的 logOR 被计算为随机效应荟萃分析中的汇总效应大小估计量。仅采用纵向设计的汇总研究（总体 N = 45,734）、孤独感评分（19 项研究，SMD = 0.27 [95% 置信区间 = 0.14–0.40]，Z = 4.02，p < .001，I 2 = 98%）和患病率发生率（8项研究，logOR = 0.33 [0.04–0.62]，Z = 2.25，p = .02，I 2 = 96%）相对于大流行前时期有所增加，且效应较小。就研究的总体 RoB、伪纵向设计、大流行前评估的时间安排和临床人群而言，结果是稳健的。影响的异质性表明，随着大流行的进展，需要进一步调查风险和保护因素，以便为有针对性的干预措施提供信息。