Effect Sizes In Meta-analyses Research Articles

Predicting anxiety-related personality traits by means of serotonergic VNTR variants STin2 and 5-HTTLPR

Polymorphisms of the serotonergic system are amongst the most commonly investigated genetic variants with respect to anxiety-related personality traits and affective disorders. Mostly the prominent 5-HTTLPR, a functional VNTR in the 5-HTT promoter region, is intensively analysed but effect sizes in meta-analyses are small and results are inconsistent. We reinvestigated the association of 5-HTTLPR with harm avoidance (HA) and neuroticism taking another functional 5-HTT-VNTR (STin2) into account, as both VNTRs have transcription regulating properties and research points to combinatorial effects on transcription efficacy. N = 2969 participants, among them 447 inpatients suffering from affective disorders, were genotyped and filled in the TCI, NEO-FFI personality inventories besides the CLEq measuring the extent of experienced stressful life events. Significant main effects for the 5-HTTLPR with inpatients carrying the L+ allele having lower HA scores as well as for the STin2 with healthy controls carrying at least one STin2.12R allele having lower neuroticism scores were observed. Besides no gene-interaction occurred. However, specific haplotype effects were observed in healthy participants as well as in the total sample. More specifically, the 12/L variant was associated with significant lower HA and neuroticism scores. Results highlight the multifactorial interplay of 5-HTT genetic variants and the use of haplotypes in association studies on anxiety-related personality traits with impact on affective disorders.

Efficacy and safety of moxibustion on cancer-related fatigue: a systematic review and meta-analysis of randomized controlled trials.

The goal of this research was to review the literature from randomized controlled trials (RCTs) on the impacts of moxibustion on cancer-related fatigue (CRF) as well as provide credible evidence to guide clinical practice. Three English electronic medical databases (PubMed, Embase, and the Cochrane Library) and two Chinese databases (China National Knowledge Infrastructure and Wanfang) were searched. Only randomized controlled trials on the effect of moxibustion on CRF were included in this systematic review. Study selection, data extraction, and validation were all carried out independently by two reviewers. The revised Cochrane Risk of Bias tool was used to assess the quality of the RCTs (RoB 2.0). The Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was applied to assess effect sizes in individual RCTs and pooled effect sizes in meta-analyses. Data were meta-analyzed using Stata (version 14.0). In a random-effects meta-analysis of 24 RCTs with 1894 participants, the aggregated standardized mean difference (SMD) revealed a statistically significant association between moxibustion and alleviation from cancer-related fatigue (SMD = - 1.66, 95% CI = - 2.05, - 1.28, p = 0.000). Pooled results, however, show significant heterogeneity (I2 = 92.5%), and the evidence is insufficient to determine whether this association varies systematically by measuring tools and moxibustion modalities. Furthermore, evidence ranging from very low to low showed that moxibustion had an immediate positive effect on patients with CRF. Moxibustion may have a therapeutic effect on cancer-related fatigue. However, further large-scale, multicenter, high-quality RCTs on moxibustion for fatigue relief and safety are still needed because of the handful of studies included and the low methodological quality.

Multi‐lingual literature searches are needed to unveil global knowledge

Multi‐lingual literature searches are needed to unveil global knowledge

Benchmarking the effectiveness of interventions to promote physical activity: A metasynthesis.

The effectiveness of physical activity interventions is typically evaluated using null hypothesis significance testing or conventional interpretations of effect size (i.e., "small," "medium," or "large"). As these criteria have recently attracted criticism, we conducted a quantitative integration of meta-analyses (a metasynthesis) in order to provide precise, numerical estimates of intervention effectiveness. The research aimed to specify the percentile distribution of effect sizes in meta-analyses of physical activity trials, and their corresponding values for different types of activity (i.e., steps per day, minutes of moderate/vigorous physical activity [MVPA], meeting World Health Organization (WHO) physical activity guidelines). Computerized searches identified 104 meta-analyses incorporating findings from 2,762 trials that met the inclusion criteria for the metasynthesis. The median effect size across all meta-analyses was d+ = .21, equivalent to an increase of 1,320 steps per day, 15.6 additional minutes of daily MVPA, and a 4.3% increase in the proportion of participants meeting WHO guidelines. Separate percentile distributions were computed for different samples (e.g., children, older adults, cancer survivors), measures of physical activity (i.e., objective vs. self-report), settings (e.g., schools, workplace), and follow-up periods (3+, 6+, and 12+ months). Conventional interpretations of effect size gravely misrepresent the effectiveness of interventions to promote physical activity. The percentile values for effect sizes, steps per days, minutes of MVPA, and percentage meeting guidelines reported here can be used to benchmark the effectiveness of future trials and should enable more informed judgments about trade-offs between effectiveness and considerations such as reach, burden, and cost. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Reproducibility of individual effect sizes in meta-analyses in psychology.

To determine the reproducibility of psychological meta-analyses, we investigated whether we could reproduce 500 primary study effect sizes drawn from 33 published meta-analyses based on the information given in the meta-analyses, and whether recomputations of primary study effect sizes altered the overall results of the meta-analysis. Results showed that almost half (k = 224) of all sampled primary effect sizes could not be reproduced based on the reported information in the meta-analysis, mostly because of incomplete or missing information on how effect sizes from primary studies were selected and computed. Overall, this led to small discrepancies in the computation of mean effect sizes, confidence intervals and heterogeneity estimates in 13 out of 33 meta-analyses. We provide recommendations to improve transparency in the reporting of the entire meta-analytic process, including the use of preregistration, data and workflow sharing, and explicit coding practices.

Treatment with kaempferol: A possible tool to restore neurogenesis in Down syndrome?

Systematic reviews of analgesics for low back pain generally include published data only. Obtaining data from unpublished trials is potentially important because they may impact effect sizes in meta-analyses. We determined whether including unpublished data from trial registries changes the effect sizes in meta-analyses of analgesics for low back pain.Trial registries were searched for unpublished data that conformed to the inclusion criteria of n = 5 individual source systematic reviews. We reproduced the meta-analyses using data available from the original reviews and then reran the same analyses with the addition of new unpublished data.Sixteen completed, unpublished, trials were eligible for inclusion in four of the source reviews. Data were available for five trials. We updated the analyses for two of the source reviews. The addition of data from two trials reduced the effect size of muscle relaxants, compared with sham, for recent-onset low back pain from −21.71 (95% CI: −28.23 to −15.19) to −2.34 (95% CI: −3.34 to −1.34) on a 0–100 scale for pain intensity. The addition of data from three trials (one enriched design) reduced the effect size of opioid analgesics, compared with sham, for chronic low back pain from −10.10 (95% CI: −12.81 to −7.39) to −9.31 (95% CI: −11.51 to −7.11). The effect reduced in the subgroup of enriched design studies, from −12.40 (95% CI: −16.90 to −7.91) to −11.34 (95% CI: −15.36 to −7.32), and in the subgroup of nonenriched design studies, from −7.27 (95% CI: −9.97 to −4.57) to −7.19 (95% CI: −9.24 to −5.14).Systematic reviews should include reports of unpublished trials. The result for muscle relaxants conflicts with the conclusion of the published review and recent international guidelines. Adding unpublished data strengthens the evidence that opioid analgesics have small effects on persistent low back pain and more clearly suggests these effects may not be clinically meaningful.

Differential effects of biological invasions on coastal blue carbon: A global review and meta‐analysis

Human-caused shifts in carbon (C) cycling and biotic exchange are defining characteristics of the Anthropocene. In marine systems, saltmarsh, seagrass, and mangrove habitats-collectively known as "blue carbon" and coastal vegetated habitats (CVHs)-are a leading sequester of global C and increasingly impacted by exotic species invasions. There is growing interest in the effect of invasion by a diverse pool of exotic species on C storage and the implications for ecosystem-based management of these systems. In a global meta-analysis, we synthesized data from 104 papers that provided 345 comparisons of habitat-level response (plant and soil C storage) from paired invaded and uninvaded sites. We found an overall net effect of significantly higher C pools in invaded CVHs amounting to 40% (±16%) higher C storage than uninvaded habitat, but effects differed among types of invaders. Elevated C storage was driven by blue C-forming plant invaders (saltmarsh grasses, seagrasses, and mangrove trees) that intensify biomass per unit area, extend and elevate coastal wetlands, and convert coastal mudflats into C-rich vegetated habitat. Introduced animal and structurally distinct primary producers had significant negative effects on C pools, driven by herbivory, trampling, and native species displacement. The role of invasion manifested differently among habitat types, with significant C storage increases in saltmarshes, decreases in seagrass, and no significant effect in mangroves. There were also counter-directional effects by the same species in different systems or locations, which underscores the importance of combining data mining with analyses of mean effect sizes in meta-analyses. Our study provides a quantitative basis for understanding differential effects of invasion on blue C habitats and will inform conservation strategies that need to balance management decisions involving invasion, C storage, and a range of other marine biodiversity and habitat functions in these coastal systems.

L’affidabilità dei criteri di inclusione nelle meta-analisi in educazione: una rassegna di studi

Reliability of meta-analysis standards in education: an overview of studies. Research syntheses, such as meta-analyses and systematic reviews, are methods for combining results of different primary studies on a certain theme. These methods have been widespread in the early eighties in educational research with the purpose of giving more reliable information to the teaching practice. As primary studies, not all the reviews carried out are reliable to inform practice on programs and strategies that are effective for learning. Although some systematic reviews and meta-analyses have weaknesses, it is possible to identify which procedures and standards are more valid and reliable for carrying out metaanalyses. This article reviews and examines studies that have evaluated methodological factors that affect effect sizes in meta-analyses of educational practices. The studies of this review have showed that the following methodological factors affect effect sizes: publication bias, sample size, study design, outcome measures and intervention duration. The conclusion specifies which inclusion criteria, based on the review results, are more reliable to carry out meta-analyses that have the objective to inform educational practices.

Publication Bias in Special Education Meta-Analyses

Publication bias involves the disproportionate representation of studies with large and significant effects in the published research. Among other problems, publication bias results in inflated omnibus effect sizes in meta-analyses, giving the impression that interventions have stronger effects than they actually do. Although evidence suggests that publication bias exists in other fields, research has not examined the issue in special education. In this study, we examined the inclusion of gray literature, testing for publication bias, the extent to which publication bias exists, the relation of including gray literature to the presence of publication bias, and differences in effect size magnitude for gray literature and published studies among 109 meta-analyses published in special education journals. We found the following: (a) 42% of meta-analyses included gray literature, (b) 33% examined publication bias, (c) meta-analyses not including gray literature were more likely to reflect publication bias, and (d) published studies had larger effect sizes than gray literature. We discuss implications and recommendations for research and practice.

The serotonin transporter polymorphism (5-HTTLPR) and personality: response style as a new endophenotype for anxiety

Although the serotonin transporter length polymorphic region (5-HTTLPR) polymorphism is an extensively-investigated genetic marker of anxiety related personality traits (neuroticism and harm avoidance) and affective disorders, effect sizes in meta-analyses are small, if present at all, and all available primary studies to date lack mandatory statistical power. Moreover, questionnaire data is prone to confounding by variables such as social desirability. Therefore, extreme response style (ERS) is suggested as a new approach to elucidate the relationship between 5-HTTLPR and negative emotionality, as it is more implicit and of high reliability. N = 1075 healthy subjects were genotyped for 5-HTTLPR and a flanking polymorphism (rs25531) and filled out the NEO Five Factor Inventory and the Temperament Character Inventory. As dependent variable the number of extreme responses across all items was calculated. Using the common genotype or the triallelic approach (including rs25531) the meta-analytic findings could not be replicated. However, there was a significant association between 5-HTTLPR and extreme response style. Carriers of the L-allele or the L'-allele, respectively, had a significantly higher number of extreme responses than homozygous SS carriers across all items of the NEO Five Factor Inventory. This finding could be replicated in an alternative personality questionnaire (Affective Neuroscience Personality Scales, ANPS). There is a long tradition in psychological assessment indicating that ERS is an implicit measure of personality. Given the positive findings of the present study, ERS qualifies as a promising endophenotype in future genetic association studies on personality and affective disorders.

The obstetric consequences of female genital mutilation/cutting: a systematic review and meta-analysis.

Various forms of female genital mutilation/cutting (FGM/C) have been performed for millennia and continue to be prevalent in parts of Africa. Although the health consequences following FGM/C have been broadly investigated, divergent study results have called into question whether FGM/C is associated with obstetric consequences. To clarify the present state of empirical research, we conducted a systematic review of the scientific literature and quantitative meta-analyses of the obstetric consequences of FGM/C. We included 44 primary studies, of which 28 were comparative, involving almost 3 million participants. The methodological study quality was generally low, but several studies reported the same outcome and were sufficiently similar to warrant pooling of effect sizes in meta-analyses. The meta-analyses results showed that prolonged labor, obstetric lacerations, instrumental delivery, obstetric hemorrhage, and difficult delivery are markedly associated with FGM/C, indicating that FGM/C is a factor in their occurrence and significantly increases the risk of delivery complications. There was no significant difference in risk with respect to cesarean section and episiotomy. These results can make up the background documentation for health promotion and health care decisions that inform work to reduce the prevalence of FGM/C and improve the quality of services related to the consequences of FGM/C.

P02 - 368 - Interactions between obsessive - compulsive symptoms and interpersonal profiles during short - term psychodynamic therapy

IntroductionAn increasing amount of outcome research supports the efficacy of Short Term Psychodynamic Psychotherapy (STPP) for a wide range of psychological disorders, reporting effect sizes in meta-analyses between 0.50 and 1.40 (for review see Shedler, 2010). Mapping mechanisms of change in the STPP process can be considered the major challenge of STPP for the decades to come.Objectives/aimsThis study focuses on STPP with Obsessive-Compulsive (OC) patients and tests the hypothesis that the progressive elimination of OC symptoms throughout an STPP process is correlated to a parallel process of change at the level of interpersonal characteristics.MethodMixed quantitative-qualitative analyses of data of Short Term Psychodynamic Therapies with four OC patients are presented. Repeated Measures analyses are performed to study intra-subject associations between intensity of OC symptoms (measured by General Health Questionnaire, GHQ-12, and Obsessive-Compulsive Inventory, OCI-R) and interpersonal characteristics (measured by Inventory of Interpersonal Problems, IIP-32).ResultsObserved associations between evolutions in general interpersonal characteristics and general complaints were significant yet inconsistent across the patients. Qualitative analyses, however, revealed similarities on the level of specific interpersonal characteristics, in this respect that all patients struggled to escape the suffocating impact of parental figures and/or romantic partners.ConclusionsRather than elaborating a general interpersonal style (cfr. Desmet et al., 2008), the results suggest that a progressive elaboration of parent-child and partner relationships is a crucial characteristic of the STPP process with OC patients. Limitations of the study are the small sample size and the absence of contrast- and control groups.