scholarly journals A Welch-type test for comparing K linear contrasts under heteroscedasticity with applications to meta-analysis

2021 ◽  
Author(s):  
Elena Kulinskaya ◽  
Emily Knight ◽  
Haiyan Gao
Keyword(s):  
Meta Analysis ◽  
Null Distribution ◽  
Effect Sizes ◽  
Sums Of Squares ◽  
Weighted Sums ◽  
Control Groups ◽  
Type Test ◽  
Linear Contrasts ◽  
One Way Anova

A test for comparing linear contrasts with heteroscedasticity, both across components of each contrast and between the contrasts, is developed under assumption of normality. The test is based on the weighted sums of squares. This is an extension of methods for weighted one-way ANOVA developed in Welch (1951) under the null, and in Kulinskaya et al. (2000) [12] underthe alternatives. We provide very accurate approximations to the null distribution and to the distribution under alter natives. The quality of these approximations is studied by simulation. The main application is the I by 2 layout which is widespread in meta-analysis. Our methods allow the homo-geneity of effect sizes across I studies to be tested, without the assumption of equal variances in the treatment and the control groups.

Does Endometriosis Disturb Mental Health and Quality of Life? A Systematic Review and Meta-Analysis

2021 ◽  
pp. 1-21
Author(s):  
Yuehan Wang ◽  
Bo Li ◽  
Yang Zhou ◽  
Yizi Wang ◽  
Xue Han ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Mental Health ◽  
Subgroup Analysis ◽  
Meta Analysis ◽  
Effect Sizes ◽  
Depression And Anxiety ◽  
Control Groups ◽  
Moderating Factors ◽  
Main Effect

<b><i>Introduction:</i></b> This study aimed to evaluate whether endometriosis could disturb the mental health and health-related quality of life (HRQoL) of patients and to provide a new prospective for further treatment of endometriosis. <b><i>Methods:</i></b> A comprehensive literature review was conducted among 4 international databases (PubMed, Embase, Web of Science, and Cochrane Library) and 2 of the largest Chinese databases (the China National Knowledge Infrastructure and Wangfang). The Newcastle-Ottawa Scale was used to assess the quality of the included articles. Six effect sizes were synthesized through a meta-analysis, and a subgroup analysis was performed to identify potential moderating factors, including types of control groups, methods of assessment, number of study groups, and origin of the study. Potential publication bias was examined using a funnel plot. <b><i>Results:</i></b> This meta-analysis pooled 44 articles from 4 continents and 13 countries and compared 6 types of main effect sizes (the odds ratio [OR] for depression, the OR for anxiety, the standardized mean difference [SMD] for depression, the SMD for anxiety, the SMD for the physical component summary [PCS] and the SMD for the mental component summary [MCS]) between endometriosis patients and controls. Except for the SMD for depression, all other effect sizes revealed statistically significant differences between the study group and the controls. The main effect size outcomes of the subgroup analysis were also similar. The type of control group (<i>I</i><sup>2</sup> = 35% in non-endometriosis control groups for the SMD of anxiety; <i>I</i><sup>2</sup> = 47% in non-endometriosis control groups for the MCS of the 36-Item Short Form Health Survey) and the continent of origin (<i>I</i><sup>2</sup> = 0% in studies from South America for the OR of depression; <i>I</i><sup>2</sup> = 47% in studies from Europe for the SMD of anxiety) may influence heterogeneity in this analysis. Additionally, depression and anxiety symptoms in patients seemed to be more apparent compared with healthy controls when the sample was smaller and when a questionnaire was used. The publication bias of the articles was acceptable. <b><i>Conclusion:</i></b> Endometriosis can disturb mental health (specifically depression and anxiety) and decrease both the mental and physical HRQoL of patients. There may be some moderating factors that we were unable to identify in the subgroup analysis, but more research is necessary to develop proper management and improve the prognosis of endometriosis patients.

scholarly journals Minor Physical Anomalies in Bipolar Disorder—A Meta-Analysis

2021 ◽  
Vol 12 ◽  
Author(s):  
Eszter Varga ◽  
András Hajnal ◽  
Alexandra Soós ◽  
Péter Hegyi ◽  
Dóra Kovács ◽  
...  
Keyword(s):  
Bipolar Disorder ◽  
Meta Analysis ◽  
Bipolar Disorders ◽  
Effect Sizes ◽  
Inclusion Criteria ◽  
Weighted Mean ◽  
Quality Of Evidence ◽  
Minor Physical Anomalies ◽  
The Brain

Introduction: Minor physical anomalies (MPAs) may reflect basic neurobiological features underlying bipolar disorders (BPD), as they are sensitive physical indicators of morphogenetic failure of the brain. Despite several researches about the presence of MPAs in BPD, the results are still controversial.Objectives: The aim of the present meta-analysis was to assess the standardized weighted mean effect sizes of MPAs in BPD and to examine if MPAs may be found predominantly in the head and/or facial regions in BPD patients compared to controls (HC).Methods: Four studies, involving 155 patients with BPD, and 187 HC, were involved in the analysis after searching the literature. For the investigation of MPAs in the peripheral (MPA-P) and in the head and facial regions (MPA-CF), two studies involving 121 BPD patients, and 133 HC passed the inclusion criteria.Results: The number of the MPAs in the BPD group was significantly higher compared to HC. Another important finding of the present study is that BPD patients' MPA-P scores do not significantly differ from those of the HC. In contrast, BPD patients' MPA-CF scores were found to be significantly higher compared to HC subjects. It is important to note that there was a low number of eligible publications included, which caused higher heterogeneity.Conclusions: Low quality of evidence suggests that MPAs are more common in patients with BPD than in HC and the higher rate of MPAs is found predominantly in the head and facial regions.

scholarly journals Effectiveness of Acupuncturing at the Sphenopalatine Ganglion Acupoint Alone for Treatment of Allergic Rhinitis: A Systematic Review and Meta-Analysis

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Qinwei Fu ◽  
Lanzhi Zhang ◽  
Yang Liu ◽  
Xinrong Li ◽  
Yepeng Yang ◽  
...  
Keyword(s):  
Systematic Review ◽  
Allergic Rhinitis ◽  
Total Effective Rate ◽  
Meta Analysis ◽  
Effective Rate ◽  
Disease Classification ◽  
Sphenopalatine Ganglion ◽  
Control Groups ◽  
Vas Score

Aim(s). To evaluate the efficiency of acupuncturing at the sphenopalatine ganglion acupoint alone for treatment of allergic rhinitis. Design. A total of ten online databases were searched to find studies published up to Jan. 2018. Primary outcome measures include the TNSS, the RQLQ score, the VAS score, total effective rate, score for signs and symptoms, and the improvement of disease classification. Study quality of each included article was evaluated by the Cochrane Collaboration risk of bias tool. A meta-analysis was conducted based on the Cochrane systematic review method by using RevMan 5.3 software. Interventions. Acupuncturing SGA alone was the only therapy in experimental group. Interventions in control groups includes sham acupuncture, acupuncturing other regular acupoints, and western medicine. Specific techniques included manual acupuncture and electroacupuncture only. Primary Outcomes. They include TNSS, RQLQ, VAS score, total effective rate, the improvement of disease classification. Results. Ten studies of eight articles involving 1004 participants were included. Result of meta-analysis showed that acupuncturing sphenopalatine ganglion acupoints alone was more effective than control groups. However, several adverse effects were reported. Conclusion. These findings show that acupuncturing the sphenopalatine ganglion acupoint alone has a potential role in alleviating nasal symptoms, improving quality of life for patients, and the effectiveness of acupuncture in the treatment of allergic rhinitis, suggesting it as a considerable therapy for allergic rhinitis. However, more studies are needed to execute a subgroup analysis of various variables and to evaluate the publication bias of the study.

scholarly journals Comparative clinical trials in psychotherapy: Have large effects been replicated?

2020 ◽  
Vol 29 ◽  
Author(s):  
Nickolas D. Frost ◽  
Thomas W. Baskin ◽  
Bruce E. Wampold
Keyword(s):  
Clinical Trials ◽  
Treatment Efficacy ◽  
Literature Search ◽  
Meta Analysis ◽  
Effect Sizes ◽  
Depression And Anxiety ◽  
Inclusion Criteria ◽  
Average Quality ◽  
Meta Analyses

Abstract Aims The purpose of this review is to examine the replication attempts of psychotherapy clinical trials for depression and anxiety. We focus specifically on replications of trials that exhibit large differences between psychotherapies. The replicability of these trials is especially important for meta-analysis, where the inclusion of false-positive trials can lead to erroneous conclusions about treatment efficacy. Methods Standard replication criteria were developed to distinguish direct from conceptual replication methodologies. Next, an exhaustive literature search was conducted for published meta-analyses of psychotherapy comparisons. Trials that exhibited large effects (d > 0.8) were culled from these meta-analyses. For each trial, a cited replication was conducted to determine if the trial had been subsequently replicated by either ‘direct’ or ‘conceptual’ methods. Finally, a broader search was conducted to examine the extent of replication efforts in the psychotherapy literature overall. Results In the meta-analytic search, a total of N = 10 meta-analyses met the inclusion criteria. From these meta-analyses, N = 12 distinct trials exhibited large effect sizes. The meta-analyses containing more than two large effect trials reported evidence for treatment superiority. A cited replication search yielded no direct replication attempts (N = 0) for the trials with large effects, and N = 4 conceptual replication attempts of average or above average quality. However, of these four attempts, only two partially corroborated the results from their original trial. Conclusion Meta-analytic reviews are influenced by trials with large effects, and it is not uncommon for these reviews to contain several such trials. Since we find no evidence that trials with such large effects are directly replicable, treatment superiority conclusions from these reviews are highly questionable. To enhance the quality of clinical science, the development of authoritative replication criteria for clinical trials is needed. Moreover, quality benchmarks should be considered before trials are included in a meta-analysis, or replications are attempted.

scholarly journals The Effectiveness of Moxibustion: An Overview During 10 Years

2011 ◽  
Vol 2011 ◽  
pp. 1-19 ◽  
Author(s):  
Song-Yi Kim ◽  
Younbyoung Chae ◽  
Seung Min Lee ◽  
Hyejung Lee ◽  
Hi-Joon Park
Keyword(s):  
Meta Analysis ◽  
Breech Presentation ◽  
Control Group ◽  
Controlled Trials ◽  
Control Groups ◽  
Randomized Controlled ◽  
Language Restriction ◽  
Digestive Disorders ◽  
General Care

Moxibustion has been used to treat various types of disease. However, there is still insufficient evidence regarding its effectiveness. This study was performed to summarize and evaluate the effectiveness of moxibustion. A search was performed for all randomized controlled trials in PubMed between January 1998 and July 2008 with no language restriction. The results yielded 47 trials in which six moxibustion types were applied to 36 diseases ranging from breech presentation to digestive disorders. Moxibustion was compared to three types of control group: general care, Oriental medical therapies or waiting list. Moxibustion was superior to the control in 14 out of 54 control groups in 46 studies. There were no significant differences among groups in 7 studies, and the outcome direction was not determined in 33 studies. Seven studies were included in a meta-analysis. Moxibustion was more effective than medication in two ulcerative colitis studies (relative risk (95% CI), 2.20 (1.37, 3.52),P= .001,I2= 0%). Overall, our results did not support the effectiveness of moxibustion in specific diseases due to the limited number and low quality of the studies and inadequate use of controls. In order to provide appropriate evidence regarding the effectiveness of moxibustion, more rigorous clinical trials using appropriate controls are warranted.

scholarly journals Is psychotherapy effective? A re-analysis of treatments for depression

2018 ◽  
Vol 28 (03) ◽  
pp. 268-274 ◽  
Author(s):  
T. Munder ◽  
C. Flückiger ◽  
F. Leichsenring ◽  
A. A. Abbass ◽  
M. J. Hilsenroth ◽  
...  
Keyword(s):  
Natural History ◽  
Publication Bias ◽  
Meta Analysis ◽  
Effect Sizes ◽  
Wait List ◽  
Control Groups ◽  
Data Set ◽  
A Value ◽  
History Of ◽  
History Of Depression

AbstractAimsThe aim of this study was to reanalyse the data from Cuijpers et al.'s (2018) meta-analysis, to examine Eysenck's claim that psychotherapy is not effective. Cuijpers et al., after correcting for bias, concluded that the effect of psychotherapy for depression was small (standardised mean difference, SMD, between 0.20 and 0.30), providing evidence that psychotherapy is not as effective as generally accepted.MethodsThe data for this study were the effect sizes included in Cuijpers et al. (2018). We removed outliers from the data set of effects, corrected for publication bias and segregated psychotherapy from other interventions. In our study, we considered wait-list (WL) controls as the most appropriate estimate of the natural history of depression without intervention.ResultsThe SMD for all interventions and for psychotherapy compared to WL controls was approximately 0.70, a value consistent with past estimates of the effectiveness of psychotherapy. Psychotherapy was also more effective than care-as-usual (SMD = 0.31) and other control groups (SMD = 0.43).ConclusionsThe re-analysis reveals that psychotherapy for adult patients diagnosed with depression is effective.

scholarly journals The comparative effectiveness of physical exercise interventions in individuals with chronic non-specific neck pain: protocol for a network meta-analysis

BMJ Open ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. e034846 ◽  
Author(s):  
Rutger MJ de Zoete ◽  
James H McAuley ◽  
Nigel R Armfield ◽  
Michele Sterling
Keyword(s):  
Physical Exercise ◽  
Neck Pain ◽  
Meta Analysis ◽  
Network Effect ◽  
Effect Sizes ◽  
Controlled Trials ◽  
Cochrane Central Register ◽  
Exercise Interventions ◽  
Meta Analyses

IntroductionNeck pain is a global burdensome problem, with a large proportion of neck pain cases becoming chronic. Although physical exercise is a commonly prescribed treatment, the evidence on the effectiveness of isolated exercise interventions remains limited. Traditional pairwise randomised controlled trials (RCTs) and meta-analyses are limited in only comparing two interventions. This protocol describes the design of a network meta-analysis, which enables a comparative investigation of all physical exercise interventions for which RCTs are available. We aim to systematically compare the effectiveness of different types of physical exercise in people with chronic non-specific neck pain.Methods and analysisNine electronic databases (AMED, CINAHL, Cochrane Central Register of Controlled Trials, Embase, MEDLINE, Physiotherapy Evidence Database, PsycINFO, Scopus and SPORTDiscus) were searched for RCTs from inception to 12 March 2019. Titles and abstract firstly, and full-text papers secondly, will be screened by two reviewers. Data will be extracted by two reviewers. The primary outcome measure is effectiveness of the intervention. Methodological quality of included studies will be assessed by two reviewers using the PEDro scale. The overall quality of evidence will be assessed with the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework, which has been adapted for network meta-analyses. The available evidence will be summarised using a network diagram. A contribution matrix will be presented to allow assessment of direct and indirect evidence. Forest plots will be constructed to visualise effects of all included exercise interventions. Pairwise effect sizes will be calculated by including all evidence available in the network. Effect measures for treatments that have not been compared in a pairwise RCT can be compared indirectly by contrasting effect sizes of comparisons with a common comparator.Ethics and disseminationThis work synthesises evidence from previously published studies and does not require ethics review or approval. A manuscript describing the findings will be submitted for publication in a peer-reviewed scientific journal.PROSPERO registration numberCRD42019126523.

Effect of exercise training on quality of life in multiple sclerosis: a meta-analysis

2008 ◽  
Vol 14 (1) ◽  
pp. 129-135 ◽  
Author(s):  
R.W. Motl ◽  
J.L. Gosney
Keyword(s):  
Quality Of Life ◽  
Multiple Sclerosis ◽  
Exercise Training ◽  
Effect Size ◽  
Meta Analysis ◽  
Effect Sizes ◽  
Training Interventions ◽  
Manual Search ◽  
Exercise Stimulus

Using meta-analytic procedures, this study examined the overall effect of exercise training interventions on quality of life (QOL) among individuals with multiple sclerosis (MS). We searched MEDLINE, PSYCHINFO and CURRENT CONTENTS PLUS for the period of 1960 to November 2006 using the key words exercise, physical activity and physical fitness in conjunction with QOL and MS. We further conducted a manual search of bibliographies of the retrieved papers as well as literature reviews and contacted study authors about additional studies. Twenty-five journal articles were located and reviewed, and only 13 provided enough data to compute effect sizes expressed as Cohen's d. One hundred and nine effect sizes were retrieved from the 13 studies with 484 MS participants and yielded a weighted mean effect size of g = 0.23 (95% CI = 0.15, 0.31). There were larger effects associated with MS-specific measures of QOL and fatigue as an index of QOL. The nature of the exercise stimulus further influenced the magnitude of the mean effect size. The cumulative evidence supports that exercise training is associated with a small improvement in QOL among individuals with MS. Multiple Sclerosis 2008; 14: 129—135. http://msj.sagepub.com

The Effects of Exercise on Mood in Older Adults: A Meta-Analytic Review

2000 ◽  
Vol 8 (4) ◽  
pp. 407-430 ◽  
Author(s):  
Shawn M. Arent ◽  
Daniel M. Landers ◽  
Jennifer L. Etnier
Keyword(s):  
Older Adults ◽  
Exercise Prescription ◽  
Meta Analysis ◽  
The Elderly ◽  
Exercise Group ◽  
Effect Sizes ◽  
Control Groups ◽  
Moderating Variables ◽  
Analytic Review ◽  
Experimental Versus

This meta-analysis examined the exercise-mood relationship in older adults. 158 effect sizes (ESs) from 32 studies were grouped intoexperimental-versus-control, gains, and correlational ESs. Each study was coded for moderator variables related to descriptive, design, participant, exercise, and mood-assessment characteristics. Experimental-versus-control ESs for negative (NA) and positive affect (PA) were 0.35 (p < .05) and 0.33 (p > .05), respectively, with an overall ES of 0.34, p < .05. The gains ESs for NA and PA in an exercise group were 0.39 (p < .05) and 0.35 (p < .05), respectively, with an overall ES of 0.38, p < .05. All effects were significantly greater than those for the control groups. Correlational ESs of 0.47 and 0.42 were found for NA and PA. respectively. It was concluded that chronic exercise is associated with improved mood in the elderly. Moderating variables and implications for exercise prescription to improve mood in the elderly are discussed.

Can Reliance be Placed on a Single Meta-Analysis?

1990 ◽  
Vol 24 (3) ◽  
pp. 405-415 ◽  
Author(s):  
Nathaniel McConaghy
Keyword(s):  
Literature Review ◽  
Effect Size ◽  
Meta Analysis ◽  
Statistical Significance ◽  
Effect Sizes ◽  
Control Groups ◽  
Consistent Finding ◽  
Placebo Controls ◽  
Effect Of Treatment ◽  
Meta Analyses

Meta-analysis replaced statistical significance with effect size in the hope of resolving controversy concerning evaluation of treatment effects. Statistical significance measured reliability of the effect of treatment, not its efficacy. It was strongly influenced by the number of subjects investigated. Effect size as assessed originally, eliminated this influence but by standardizing the size of the treatment effect could distort it. Meta-analyses which combine the results of studies which employ different subject types, outcome measures, treatment aims, no-treatment rather than placebo controls or therapists with varying experience can be misleading. To ensure discussion of these variables meta-analyses should be used as an aid rather than a substitute for literature review. While meta-analyses produce contradictory findings, it seems unwise to rely on the conclusions of an individual analysis. Their consistent finding that placebo treatments obtain markedly higher effect sizes than no treatment hopefully will render the use of untreated control groups obsolete.

Sign in / Sign up

Export Citation Format

Share Document