scholarly journals Association of bisphenol A with puberty timing: a meta-analysis

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Hui Meng ◽  
Yunping Zhou ◽  
Yunxia Jiang
Keyword(s):  
Bisphenol A ◽  
Confidence Intervals ◽  
Random Effects ◽  
Strong Correlation ◽  
Fixed Effects ◽  
Meta Analysis ◽  
Random Effects Models ◽  
Study Heterogeneity ◽  
The Relationship ◽  
Prevalence Ratios

AbstractObjectivesThe results of existing studies on bisphenol A (BPA) and puberty timing did not reach a consensus. Thereby we performed this meta-analytic study to explore the association between BPA exposure in urine and puberty timing.MethodsMeta-analysis of the pooled odds ratios (OR), prevalence ratios (PR) or hazards ratios (HR) with 95% confidence intervals (CI) were calculated and estimated using fixed-effects or random-effects models based on between-study heterogeneity.ResultsA total of 10 studies involving 5621 subjects were finally included. The meta-analysis showed that BPA exposure was weakly associated with thelarche (PR: 0.96, 95% CI: 0.93–0.99), while no association was found between BPA exposure and menarche (HR: 0.99, 95% CI: 0.89–1.12; OR: 1.02, 95% CI: 0.73–1.43), and pubarche (OR: 1.00, 95% CI: 0.79–1.26; PR: 1.00, 95% CI: 0.95–1.05).ConclusionsThere was no strong correlation between BPA exposure and puberty timing. Further studies with large sample sizes are needed to verify the relationship between BPA and puberty timing.

EXPRESS: A meta-analysis of aspirin and subarachnoid haemorrhage in patients with intracranial aneurysms yields different results to the general population

2021 ◽  
pp. 174749302110048
Author(s):  
Frederick Ewbank ◽  
Jacqueline Birks ◽  
Diederik Bulters
Keyword(s):  
General Population ◽  
Subarachnoid Haemorrhage ◽  
Confidence Intervals ◽  
Random Effects ◽  
Intracranial Aneurysms ◽  
Meta Analysis ◽  
Risk Of Bias ◽  
Random Effects Models ◽  
Hazard Ratios ◽  
Unruptured Intracranial Aneurysms

Abstract Background Some studies have shown a protective association between aspirin use and subarachnoid haemorrhage (SAH). Other studies have found no relationship or the reverse. These studies differ in their study populations and definitions of SAH. Aims Our aim was to establish 1) if there is an association between aspirin and SAH, 2) how this differs between the general population and those with intracranial aneurysms. Summary of review Studies reporting aspirin use and the occurrence of SAH were included and grouped based on population (general population vs aneurysm population). Odds ratios, hazard ratios and confidence intervals were combined in random-effects models. 11 studies were included. Overall, there was an association between aspirin and SAH (OR 0.68 [0.48, 0.96]). However, populations were diverse and heterogeneity between studies high (p<0.00001), questioning the validity of combining these studies and justifying analysis by population. In the general population there was no difference in aspirin use between individuals with and without SAH (OR 1.15 [0.96, 1.38]). In patients with intracranial aneurysms, aspirin use was greater in patients without SAH (OR 0.37 [0.24, 0.58]), although these studies were at higher risk of bias. Conclusions There is an association between aspirin use and SAH in patients with intracranial aneurysms. This apparent protective relationship is not seen in the general population. Prospective randomised studies are required to further investigate the effect of aspirin on unruptured intracranial aneurysms.

The relationship between migraine and infant colic: A systematic review and meta-analysis

Cephalalgia ◽  
2014 ◽  
Vol 35 (1) ◽  
pp. 63-72 ◽  
Author(s):  
Amy A Gelfand ◽  
Peter J Goadsby ◽  
I Elaine Allen
Keyword(s):  
Systematic Review ◽  
Random Effects ◽  
Odds Ratio ◽  
Fixed Effects ◽  
Meta Analysis ◽  
Random Effects Model ◽  
Fixed Effects Model ◽  
Primary Analysis ◽  
Infant Colic ◽  
The Relationship

Context Infant colic is a common and distressing disorder of early infancy. Its etiology is unknown, making treatment challenging. Several articles have suggested a link to migraine. Objective The objective of this article was to perform a systematic review and, if appropriate, a meta-analysis of the studies on the relationship between infant colic and migraine. Data sources Studies were identified by searching PubMed and ScienceDirect and by hand-searching references and conference proceedings. Study selection For the primary analysis, studies specifically designed to measure the association between colic and migraine were included. For the secondary analysis, studies that collected data on colic and migraine but were designed for another primary research question were also included. Data extraction Data were abstracted from the original studies, through communication with study authors, or both. Two authors independently abstracted data. Main outcomes and measures The main outcome measure was the association between infant colic and migraine using both a fixed-effects model and a more conservative random-effects model. Results Three studies were included in the primary analysis; the odds ratio for the association between migraine and infant colic was 6.5 (4.6–8.9, p < 0.001) for the fixed-effects model and 5.6 (3.3–9.5, p = 0.004) for the random-effects model. In a sensitivity analysis wherein the study with the largest effect size was removed, the odds ratio was 3.6 (95% CI 1.7–7.6, p = 0.001) for both the fixed-effects model and random-effects model. Conclusions In this meta-analysis, infant colic was associated with increased odds of migraine. If infant colic is a migrainous disorder, this would have important implications for treatment. The main limitation of this meta-analysis was the relatively small number of studies included.

scholarly journals Metaanalysis of the relationship between violent video game play and physical aggression over time

2018 ◽  
Vol 115 (40) ◽  
pp. 9882-9888 ◽  
Author(s):  
Anna T. Prescott ◽  
James D. Sargent ◽  
Jay G. Hull
Keyword(s):  
Random Effects ◽  
Video Game ◽  
Physical Aggression ◽  
Fixed Effects ◽  
Time Lags ◽  
Random Effects Models ◽  
Video Game Play ◽  
Game Violence ◽  
The Relationship ◽  
Significant Moderator

To clarify and quantify the influence of video game violence (VGV) on aggressive behavior, we conducted a metaanalysis of all prospective studies to date that assessed the relation between exposure to VGV and subsequent overt physical aggression. The search strategy identified 24 studies with over 17,000 participants and time lags ranging from 3 months to 4 years. The samples comprised various nationalities and ethnicities with mean ages from 9 to 19 years. For each study we obtained the standardized regression coefficient for the prospective effect of VGV on subsequent aggression, controlling for baseline aggression. VGV was related to aggression using both fixed [β = 0.113, 95% CI = (0.098, 0.128)] and random effects models [β = 0.106 (0.078, 0.134)]. When all available covariates were included, the size of the effect remained significant for both models [β = 0.080 (0.065, 0.094) and β = 0.078 (0.053, 0.102), respectively]. No evidence of publication bias was found. Ethnicity was a statistically significant moderator for the fixed-effects models (P≤ 0.011) but not for the random-effects models. Stratified analyses indicated the effect was largest among Whites, intermediate among Asians, and nonsignificant among Hispanics. Discussion focuses on the implications of such findings for current debates regarding the effects of violent video games on physical aggression.

Comparative Effectiveness of Lenalidomide Plus Dexamethasone for the Treatment of Refractory/Relapsed Multiple Myeloma: A Systematic Review and Mixed Treatment Comparison

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 4076-4076
Author(s):  
Sallie Stradwick ◽  
Nick Freemantle ◽  
John Snowden ◽  
Felipe Rodrigues ◽  
Nic Brereton
Keyword(s):  
Multiple Myeloma ◽  
Combination Therapy ◽  
Confidence Intervals ◽  
Random Effects ◽  
Comparative Effectiveness ◽  
Fixed Effects ◽  
Meta Analysis ◽  
Treatment Comparison ◽  
Mixed Treatment ◽  
Secondary Outcomes

Abstract Abstract 4076 OBJECTIVES: To evaluate the comparative effectiveness of lenalidomide (25 mg) plus dexamethasone (40 mg) (LEN/dex) for the treatment of relapsed/refractory multiple myeloma (RRMM) compared to thalidomide and bendamustine. Primary outcome of interest was time to progression (TTP). Secondary outcomes of interest were overall response rates (ORR) and overall survival (OS). METHODS: A comprehensive systematic literature review was conducted to identify any randomised controlled trials (RCTs) investigating the clinical efficacy of specified therapies for the treatment of RRMM. Specified therapies included lenalidomide, thalidomide and bendamustine. Of these therapies, only LEN/dex combination therapy is approved in RRMM but bendamustine and thalidomide (monotherapy or in combination with dexamethasone) have also shown activity in the treatment of myeloma. Electronic databases were searched from March 2002 to 2012 (language unrestricted. Randomized clinical trials were independently evaluated against predetermined criteria for inclusion and determined to be eligible for the meta-analysis prior to any outcome assessment. Fixed effects and random effects mixed-treatment comparisons (MTC) were carried out, adopting the methods described by Lu and Ades1. MTCs estimate the comparative effectiveness of multiple treatments using an evidence base of trials that individually do not compare all treatment options. Results for TTP were reported as hazard ratios (HR) and 95% confidence intervals and an associated probability of best treatment. Results for binary variables (ORR, OS) were reported as odds ratios (OR) and 95% confidence intervals. RESULTS: Sixteen original RCTs met the initial inclusion criteria; twelve (N = 3,590), nine (N = 3,350) and six (N = 2,295) of which were able to be connected to form a network of evidence which provided the heterogeneous trial base for MTC analysis of ORR, OS, and TTP comparison, respectively. Two trials directly investigated the efficacy of LEN/dex (N = 353) and three trials assessed the efficacy of thalidomide monotherapy (N = 785). No RCTs were identified that investigated the efficacy of bendamustine or thalidomide/dexamethasone combination therapy in RRMM. There were too few studies (investigating treatment arms of interest) relative to the number of trials in the network to formally estimate or test for heterogeneity. Therefore a fixed effects network meta-analysis was used instead of a random effects network meta-analysis. Comparability of trial populations was assessed and discussed in detail since these could not be adjusted for in the statistical model. Age, sex, baseline disease characteristics, time since diagnosis and medical history were similar between study populations. TTP analysis was statistically significant and favoured LEN/dex over thalidomide monotherapy: HR = 2.34 [1.31, 4.17]. The associated probability of LEN/dex being the best treatment within the evidence network is 97.9%. Secondary outcomes analysis were also statistically significant in favour of LEN/dex over thalidomide monotherapy (ORR: OR = 10.48 [4.75, 22.81]; OS: OR = 1.43 [1.12, 1.84]). CONCLUSIONS: Results demonstrated statistically significant superiority of lenalidomide plus dexamethasone therapy versus thalidomide monotherapy for the treatment of RRMM. No analyses were possible versus bendamustine or thalidomide/dexamethasone combination therapy due to the lack of RCTs investigating the efficacy of these therapeutic regimens in RRMM. Disclosures: Stradwick: Celgene International: Consultancy. Freemantle:BresMed: Consultancy. Off Label Use: Thalidomide monotherapy activity in the treatment of myeloma. Brereton:Celgene International: Consultancy.

scholarly journals Prognostic Role of Matrix Metalloproteinases in Cervical Cancer: A Meta-Analysis

2021 ◽  
Vol 28 ◽  
pp. 107327482110337
Author(s):  
Weiwei Chen ◽  
Shenjiao Huang ◽  
Kun Shi ◽  
Lisha Yi ◽  
Yaqiong Liu ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Matrix Metalloproteinases ◽  
Random Effects ◽  
Fixed Effects ◽  
Prognostic Value ◽  
Meta Analysis ◽  
Free Survival ◽  
Random Effects Models ◽  
Registration Number ◽  
Meta Analyses

Objective Studies have published the association between the expression of matrix metalloproteinases (MMPs) and the outcome of cervical cancer. However, the prognostic value in cervical cancer remains controversial. This meta-analysis was conducted to evaluate the prognostic functions of MMP expression in cervical cancer. Methods A comprehensive search of PubMed, Embase, and Web of Science databases was conducted to identify the eligible studies according to defined selection and excluding criteria and analyzed according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Fixed and random effects models were evaluated through the hazard ratios (HRs) and 95% confidence intervals (CIs) to estimate the overall survival (OS), recurrence-free survival (RFS), and progress-free survival (PFS). Results A total of 18 eligible studies including 1967 patients were analyzed for prognostic value. Totally 16 selected studies including 21 tests were relevant to the cervical cancer OS, 4 studies focused on RFS, and 1 study on PFS. The combined pooled HRs and 95% CIs of OS were calculated with random-effects models (HR = 1.64, 95% CI = 1.01–2.65, P = .000). In the subgroup analysis for OS, there was no heterogeneity in MMP-2 (I2 = .0%, P = .880), MMP-1 (I2 = .0%, P = .587), and MMP-14 (I2 = 28.3%, P = .248). In MMP-7 and MMP-9, the heterogeneities were obvious (I2 = 99.2% ( P = .000) and I2 = 77.9% ( P = .000), respectively). The pooled HRs and 95% CIs of RFS were calculated with fixed-effects models (HR = 2.22, 95% CI = 1.38–3.58, P = .001) and PFS (HR = 2.29, 95% CI = 1.14–4.58, P = .035). Conclusions The results indicated that MMP overexpression was associated with shorter OS and RFS in cervical cancer patients. It suggested that MMP overexpression might be a poor prognostic marker in cervical cancer. Research Registry Registration Number: reviewregistry 1159.

Meta-analysis in Sociological Research: Power and Heterogeneity

2019 ◽  
pp. 004912411988247 ◽  
Author(s):  
Guangyu Tong ◽  
Guang Guo
Keyword(s):  
Random Effects ◽  
Science Studies ◽  
Meta Analysis ◽  
Sociological Research ◽  
Random Effects Models ◽  
Sociological Inquiry ◽  
Wide Range ◽  
Fixed And Random Effects ◽  
Study Heterogeneity ◽  
Analysis Models

Meta-analysis is a statistical method that combines quantitative findings from previous studies. It has been increasingly used to obtain more credible results in a wide range of scientific fields. Combining the results of relevant studies allows researchers to leverage study similarities while modeling potential sources of between-study heterogeneity. This article provides a review of the core methodologies of meta-analysis that we consider most relevant to sociological research. After developing the foundation of the fixed- and random-effects models of meta-analysis models, this article illustrates the utility of the method with regression coefficients reported from two sets of social science studies. We explain the various steps of the process including constructing the meta-sample from primary studies, estimating the fixed- and random-effects models, analyzing the source of heterogeneity across studies, and assessing publication bias. We conclude with a discussion of steps that could be taken to strengthen the development of meta-analysis in sociological research, which will eventually increase the credibility of sociological inquiry via a knowledge-cumulative process.

Meta Analysis of Study Habits and Academic Achievement

2021 ◽  
Vol 8 (4) ◽  
pp. 139-145
Author(s):  
M Elango ◽  
G Manimozhi
Keyword(s):  
College Students ◽  
Academic Achievement ◽  
Random Effects ◽  
Fixed Effects ◽  
Meta Analysis ◽  
Study Habits ◽  
Random Effects Model ◽  
Inclusion Criteria ◽  
Analytical Review ◽  
The Relationship

A Meta analytical review investigated the study habits and academic achievement of school and college students. In this study the sample consists of twenty seven reviews based on study habits and academic achievement/ performance. The sample of the review based on inclusion criteria such as study habits and academic achievement. The review was collected by following details such as title of the study, Name of the author, Sample of the study, correlation Value and findings of the study. The Meta analysis is on the relationship between study habits and academic achievement. The main aim of the study is to find the fixed effects, random effects model values, Heterogeneity and forest plots. A Meta analysis of research paper was formed the conclusion.

scholarly journals The effect of cooperative learning on academic achievement: A meta-analysis on the relationship between the study group size and effect size İşbirlikli öğrenmenin başarıya etkisi: Çalışma grubu ile etki büyüklüğü arasındaki ilişkiye dair bir meta analiz çalışması

2017 ◽  
Vol 14 (1) ◽  
pp. 473 ◽  
Author(s):  
Murat Tuncer ◽  
Melih Dikmen
Keyword(s):  
Cooperative Learning ◽  
Random Effects ◽  
Effect Size ◽  
Fixed Effects ◽  
Meta Analysis ◽  
Experimental Studies ◽  
Study Group ◽  
Random Effects Model ◽  
Learning Groups ◽  
The Relationship

The purpose of this study was to determine the effect of cooperative learning on achievement and the relationship between the study group and effect size by means of meta-analysis. Meta-analysis is the method employed in order to statistically analyze the quantitative data collected in independent and multiple studies carried out on similar topics, and to reach a general judgment regarding the results of these studies.  Certain criteria were used in order to decide which researches would be included in the meta-analysis. Based on these criteria, it was decided to include 6 experimental studies in the meta-analysis. As a result, for the six studies, the effect size calculated within 95 % confidence interval has proved to be .518 based on random effects model. When two studies with the largest learning groups are excluded from the research respectively, firstly this effect size increases to .528, later it is calculated as .817 without any model discrimination. When effect size intervals in literature (≥ 0.5: strong, ≥ 0.3: moderate and  ≥ .01 weak) is taken into consideration, the effect of cooperative learning on achievement has been observed as  “Strong”. In addition to this, contrary to some views in literature, it has been seen that large learning groups have higher standard errors and a bigger effect size has been achieved when such studies have been excluded from the analysis. What is more, even the limitation of fixed effects model has disappeared, and the effect size calculated in fixed effects and random effects model has been balanced.  ÖzetBu araştırmanın amacı, işbirlikli öğrenmenin başarı üzerindeki etkisini ve çalışma grubu ile etki büyüklüğü arasındaki ilişkiyi meta-analiz yöntemiyle belirlemektir. Meta-analiz, benzer konularda yapılmış birbirinden bağımsız ve çok sayıda çalışmadan elde edilmiş sayısal verileri istatistiksel olarak analiz etme ve bu çalışmaların sonuçları hakkında genel bir yargıya varma yöntemidir. Hangi araştırmaların meta-analize dâhil edileceğine yönelik seçimlerin yapılmasında belirli ölçütler kullanılmıştır. Bu ölçütlere dayalı olarak 6 adet deneysel araştırmanın meta-analize dâhil edilmesine karar verilmiştir. Sonuç olarak; altı çalışma için %95 güven aralığında hesaplanan etki büyüklüğü rastgele etkiler modeline göre .518’dir. En büyük çalışma grubuna sahip iki araştırma sırasıyla araştırma dışında tutulduğunda bu etki büyüklüğü önce .528’ e çıkmakta, sonrasında ise model ayrımı olmaksızın .817 olarak hesaplanmaktadır. Alan yazındaki etki büyüklüğü aralıkları (≥ 0.5: güçlü, ≥ 0.3: orta düzey ve ≥ .01 zayıf) dikkate alındığında işbirlikli öğrenmenin başarı üzerindeki etkisi “Güçlü” bir etki olarak gözlenmiştir. Ayrıca alan yazındaki bazı görüşlerin aksine büyük çalışma gruplarının standart hatalarının daha yüksek olduğu, bu araştırmaların analiz dışında tutulması ile daha büyük etki büyüklüklerine ulaşıldığı, hatta sabit etki modelinin sınırlılığının bile ortadan kalktığı, sabit etki ve rastgele etki modelinde hesaplanan etki büyüklüğünün eşitlendiği görülmüştür.

scholarly journals Comorbidities increase the risk of severity and mortality in COVID-19 patients: a systematic review and meta-analysis

2021 ◽  
Vol 10 (2) ◽  
pp. e50010212533
Author(s):  
Edilson Leite de Moura ◽  
Jean Moises Ferreira ◽  
Ana Caroline Melo dos Santos ◽  
Denise Macedo da Silva ◽  
Maria Lidiane Ferreira da Silva ◽  
...  
Keyword(s):  
Fixed Effects ◽  
Web Of Science ◽  
Meta Analysis ◽  
Cerebrovascular Diseases ◽  
Poor Clinical Outcome ◽  
Random Effects Models ◽  
Risk Of Death ◽  
Increased Risk ◽  
Retrospective Cohort Studies ◽  
The Relationship

Introduction: Several studies have shown that patients with comorbidities present a poor clinical outcome of COVID-19, but the conclusions are not yet consolidated. We conducted a meta-analysis to evaluate the relationship between the preexistent conditions (comorbidities) in patients infected with SARS-CoV-2 and the outcome of COVID-19. Methods: PubMed, Science Direct, ISI Web of Science and Scopus databases were examined up to November 2020. We calculated the pooled odds ratio (OR) with 95% confidence interval, using fixed-effects or random-effects models. Results: A total of 48 retrospective cohort studies with 344,290 COVID-19 patients were included in the meta-analysis. The pooled results showed that hypertension, diabetes, cardiovascular, chronic pulmonary, chronic kidney and cerebrovascular diseases increase the risk of severity and mortality in COVID-19 patients. Moreover, malignancy was associated with an increased risk of death from COVID-19. Conclusions: The comorbidities previously mentioned may be important predictors of poor outcome of COVID-19, contributing to the prognosis of severe cases of the disease.

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