Association between physical activity and digestive-system cancer: An updated systematic review and meta-analysis

BackgroundPhysical activity (PA) may have an impact on digestive-system cancer (DSC) by improving insulin sensitivity and anticancer immune function and by reducing the exposure of the digestive tract to carcinogens by stimulating gastrointestinal motility, thus reducing transit time. The current study aimed to determine the effect of PA on different types of DSC via a systematic review and meta-analysis.MethodsIn accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we searched for relevant studies in PubMed, Embase, Web of Science, Cochrane Library, and China National Knowledge Infrastructure. Using a random effects model, the relationship between PA and different types of DSC was analyzed.ResultsThe data used for meta-analysis were derived from 161 risk estimates in 47 studies involving 5,797,768 participants and 55,162 cases. We assessed the pooled associations between high vs. low PA levels and the risk of DSC (risk ratio (RR)  = 0.82, 95% confidence interval (95%CI): 0.79–0.85), colon cancer (RR = 0.81, 95%CI: 0.76–0.87), rectal cancer (RR = 0.88, 95%CI: 0.80–0.98), colorectal cancer (RR = 0.77, 95%CI: 0.69–0.85), gallbladder cancer (RR = 0.79, 95%CI: 0.64–0.98), gastric cancer (RR = 0.83, 95%CI: 0.76–0.91), liver cancer (RR = 0.73, 0.60–0.89), oropharyngeal cancer (RR = 0.79, 95%CI: 0.72–0.87), and pancreatic cancer (RR = 0.85, 95%CI: 0.78–0.93). The findings were comparable between case-control studies (RR = 0.73, 95%CI: 0.68–0.78) and prospective cohort studies (RR = 0.88, 95%CI: 0.80–0.91). The meta-analysis of 9 studies reporting low, moderate, and high PA levels, with 17 risk estimates, showed that compared to low PA, moderate PA may also reduce the risk of DSC (RR = 0.89, 95%CI: 0.80–1.00), while compared to moderate PA, high PA seemed to slightly increase the risk of DSC, although the results were not statistically significant (RR = 1.11, 95%CI: 0.94–1.32). In addition, limited evidence from 5 studies suggested that meeting the international PA guidelines might not significantly reduce the risk of DSC (RR = 0.96, 95%CI: 0.91–1.02).ConclusionCompared to previous research, this systematic review has provided more comprehensive information about the inverse relationship between PA and DSC risk. The updated evidence from the current meta-analysis indicates that a moderate-to-high PA level is a common protective factor that can significantly lower the overall risk of DSC. However, the reduction rate for specific cancers may vary. In addition, limited evidence suggests that meeting the international PA guidelines might not significantly reduce the risk of DSC. Thus, future studies must be conducted to determine the optimal dosage, frequency, intensity, and duration of PA required to reduce DSC risk effectively.     

Predicting child maltreatment: A meta-analysis of the predictive validity of risk assessment instruments

Risk assessment is crucial in preventing child maltreatment since it can identify high-risk cases in need of child protection intervention. Despite widespread use of risk assessment instruments in child welfare, it is unknown how well these instruments predict maltreatment and what instrument characteristics are associated with higher levels of predictive validity. Therefore, a multilevel meta-analysis was conducted to examine the predictive accuracy of (characteristics of) risk assessment instruments. A literature search yielded 30 independent studies (N = 87,329) examining the predictive validity of 27 different risk assessment instruments. From these studies, 67 effect sizes could be extracted. Overall, a medium significant effect was found (AUC = 0.681), indicating a moderate predictive accuracy. Moderator analyses revealed that onset of maltreatment can be better predicted than recurrence of maltreatment, which is a promising finding for early detection and prevention of child maltreatment. In addition, actuarial instruments were found to outperform clinical instruments. To bring risk and needs assessment in child welfare to a higher level, actuarial instruments should be further developed and strengthened by distinguishing risk assessment from needs assessment and by integrating risk assessment with case management.     

Is short-term therapy really sufficient to eradicate Helicobacter pylori infection?

Objective:The aim of our study was to perform a systematic review and meta-analysis of the efficacy of short-term protocols for Helicobacter pylori eradication and to review the safety and adverse profiles of these eradication protocols.Methods:Literatures were located through electronic searches by PubMed,Medline,ISI Web of Knowledge,and Cochrane Library using the relevant terms.Abstracts of important meetings were searched manually in some journal supplements.Additional bibliographies were identified from the reference lists of identified studies.Three independent reviewers systemically identified randomized controlled trials(RCTs) comparing short-duration protocols vs.7-d proton pump inhibitor(PPI)-based triple protocols,as well as studies reporting eradication rates of short-duration protocols for H.pylori.Summary effect size was calculated as relative risk(RR) and 95% confidence intervals(CI) using Review Manager 4.2,and P0.05 was defined as statistically significant in all analyses.Results:Among 90 abstracts retrieved,15 studies were analyzed,including a total of 30 treatment regimens with 1856 subjects.Mean intention-to-treat(ITT) cure rates of 63.2% and 81.3% were achieved with short-term protocols and 7-d PPI-containing protocols,respectively.Per-protocol(PP)-based overall cure rates were 66.6% and 86.1%,respectively.Short-term therapy was inferior to 7-d triple regimen(P0.00001).After sub-analysis,however,comparing the effects of ≥3-d protocols and 7-d triple protocols,the cumulative ITT RR was 0.95(P=0.26),and PP RR was 0.95(P=0.10),without significant heterogeneity.Moreover,slightly fewer adverse-effects were found in short-term protocols.Conclusions:Although more economical,short-duration protocols are inferior to 7-d PPI-based triple protocols with regarding to eradication rate of H.pylori.Protocols of more than 3 d,however,may be equivalent to 7-d protocols.     

What matters for student learning outcomes: A meta-analysis of studies exploring factors of effective teaching

Meta-analysis comprises a powerful tool for synthesizing prior research and empirically validating theoretical frameworks. Using this tool and the dynamic model of educational effectiveness as a guiding framework, in this paper we present a meta-analysis of 167 studies investigating the impact of teaching factors on student achievement. The factors of the dynamic model were found to be moderately associated with student achievement; in contrast, factors not included in the model were weakly associated with student learning, with the exception of two factors associated with constructivism. In discussing the study findings, we consider their theoretical, methodological, and practical implications.     

Effectiveness of grade retention: A systematic review and meta-analysis

Research on the effectiveness of grade retention has a long history, yet, has seen an upsurge during the last decade. In this study, we review 84 recent, methodologically sound studies estimating effects of retention in grades K-12 on repeaters' and nonrepeaters' development, in a variety of countries across the world, disentangling grade and age comparison results. Based on vote counting analysis and three-level metaregression analysis we find grade retention to have an average zero effect, indicating that repeaters and non-repeaters seem to show a similar development, on average. At the same time, we find grade retention effects to differ according to some specific effect and study characteristics. More specifically, grade retention seems less effective in countries applying a mixture of grade retention and tracking to tackle student heterogeneity, and when repeaters are compared with non-repeaters of the same age. Conversely, grade retention seems more effective in countries using strategies such as ability grouping, setting, and streaming to deal with student heterogeneity. Positive effects also seem to arise when studying students' psychosocial functioning, when investigating short-run effects, when comparing repeaters with their younger non-retained grade-mates, and when evaluating effects via a regression discontinuity method.     

Academic achievement of students without special educational needs in inclusive classrooms: A meta-analysis

This article presents a meta-analysis that attempts to establish how the presence of students with special educational needs in the classroom impacts students without special educational needs. We meta-analyzed 47 studies that met the inclusion criteria, covering a total sample of almost 4 800 000 students. The overall effect was positive and statistically significant but weak, d = 0.12 (95% CI: 0.02, 0.23). A number of moderators, including the country of study, the manner of implementation (intervention studies versus regular school practice), the educational team composition, the level and type of disorders in students with special educational needs, and finally educational stage were examined. We discuss the findings in terms of assumptions and controversies surrounding the very concept of inclusive education.     

Catechol-O-methyltransferase (COMT) Val158Met Polymorphism and Susceptibility to Alcohol Dependence

Catechol-O-methyl transferase (COMT) enzyme catalyzes the metabolism of dopamine and other catechols in the brain. Several articles investigated catechol-O-methyltransferase (COMT) Val158Met polymorphism as risk factor for alcohol dependence (AD) but the results were inconclusive. The aim of present meta-analysis was to evaluate the association of Val158Met (COMT) polymorphism with AD. Authors performed keyword search of the 4 electronic databases—Pubmed, Google Scholar, Springer Link and Science Direct databases up to December 31, 2019. Total eighteen studies that investigated the association of Val158Met polymorphism with AD were retrieved. The pooled results from the meta-analysis (2278 AD cases and 3717 healthy controls) did not show association with AD using all 5 genetic models (allele contrast model: OR = 1.02, 95% CI = 0.90–1.14, p = 0.03; homozygote model: OR = 1.06, 95% CI = 0.81–1.38, p = 0.69; dominant model: OR = 0.99, 95% CI = 0.85–1.14, p = 0.87; co-dominant model: OR = 0.97, 95% CI = 0.86–1.11, p = 0.71; recessive model: OR = 1.05;95% CI = 0.85–1.29, p = 0.61). Results of subgroup analysis showed that Val158Met is not risk for AD in Asian and Caucasian population. In conclusion, COMT Val158Met is not a risk factor for alcohol dependence.     

人力资源管理实践与知识分享关系的元分析

国内外对人力资源管理实践与知识分享的关系已经作出了相当程度研究,然而国内尚缺乏一个系统、客观的总结和评价。以2000至2013年间的35篇国内外研究文献为样本,以元分析方法探讨人力资源管理实践与知识分享之间的关系。结果表明两者间效应值具有显著正相关,调节变量分析显示人力资源管理实践的测量类型是效应量之间产生异质性的原因。在此基础上提出促进知识分享的人力资源管理建议以及未来研究方向。     

伸展练习对DOMS的影响

目的:探讨伸展练习对DOMS的影响。方法:使用元分析方法,查阅相关数据库,对符合标准的11篇原始文献使用元分析软件进行统计分析。结果:伸展练习对DOMS的影响在运动后24、48、72 h其总体效应量估计值分别是-0.78、-0.84、-0.39,效应量差异具有统计学意义(P<0.05)。异质性检验表明,所采用的研究数据均符合随机效应模型,进行亚组分析发现,伸展练习的效果与研究的组间设计、牵伸时间、干预的时间相关(P<0.05)。结论:运动前后进行伸展练习可以缓解DOMS,但受到一些因素的影响。