ABSTRACT
Breast cancer is a common cancer in which patients are highly susceptible to different sleep disturbances. However, current evidence lacked consistency in methodologies in investigating the prevalence of sleep disturbances among breast cancer survivors. The review aims to (1) investigate the global prevalence of sleep disturbances among breast cancer survivors; and (2) investigate the factors influencing the prevalence estimates. A comprehensive search was conducted in 8 databases using a 3-step approach, up to January 2022. The Newcastle-Ottawa Scale and Cochrane risk of bias tool were used to evaluate the quality of individual studies. Meta-analysis, meta-regression, and subgroup analysis were performed using R software. Certainty of evidence was assessed using Grading of Recommendations, Assessment, Development, and Evaluations criteria. A total of 51 studies were selected involving 28,036 breast cancer survivors across 17 countries. The global prevalence of poor sleep quality was 62%, different severities of insomnia were 3%-32%, and excessive daytime sleepiness was 24%. Subgroup analyses showed that a significantly higher prevalence of poor sleep quality was found in breast cancer survivors during treatment compared with pre- or post-treatment. No significant covariates were found in a series of meta-regression analyses. The majority (73.5%) of individual studies were high quality but the certainty of the evidence was low or very low according to Grading of Recommendations, Assessment, Development, and Evaluations criteria. More than half of breast cancer survivors have sleep disturbances, so developing a strategic intervention is warranted. Given the low or very low certainty of the evidence, a robust design for large-scale research is crucial in the future.
ABSTRACT
BACKGROUND: While the world's population ages, social isolation has continued to increase globally. However, no review exists on the prevalence of social isolation among community-dwelling older adults, and the global prevalence remains uncertain. This study aims to estimate the global prevalence of social isolation among community-dwelling older adults and to identify potential covariates including study characteristics (methodological diversity) or populations (clinical diversity) that contribute to the heterogeneity. METHODS: This review searched through seven search engines and databases. The meta-analysis was conducted using the metafor package in the R software. The random-effects model was used to calculate the prevalence rates. Cochran's Q statistics and I2 statistics were used to assess the statistical heterogeneity of prevalence estimates. Studies were appraised using the Newcastle-Ottawa Scale and the Grading of Recommendations, Assessment, Development, and Evaluations criteria for the quality of individual articles and the certainty of the evidence, respectively. RESULTS: A total of 41 studies were selected from databases and reference lists. The pooled prevalence rate was 25% (95% CI: 21.0-30.0). The sample size was found to be a significant covariate of the prevalence estimate in the subgroup analysis. CONCLUSIONS: We found 13 high-quality studies, but the overall quality of evidence very low. This study provides the prevalence of social isolation in community-dwelling older adults, identifying vulnerable groups for targeted intervention. Well-designed observational research with standard measures is recommended for future studies.
