Multivariate fixed- and random-effects models for summarizing ordinal data in meta-analysis of diagnostic staging studies

2010 ◽  
Vol 1 (2) ◽  
pp. 136-148 ◽  
Author(s):  
Shandra Bipat ◽  
Aeilko H. Zwinderman
Keyword(s):  
Random Effects ◽  
Ordinal Data ◽  
Meta Analysis ◽  
Random Effects Models ◽  
Fixed And Random Effects

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.

Fixed- and random-effects models in meta-analysis.

1998 ◽  
Vol 3 (4) ◽  
pp. 486-504 ◽  
Author(s):  
Larry V. Hedges ◽  
Jack L. Vevea
Keyword(s):  
Random Effects ◽  
Meta Analysis ◽  
Random Effects Models ◽  
Fixed And Random Effects

Detecting and correcting for publication bias in meta-analysis – A truncated normal distribution approach

2016 ◽  
Vol 27 (9) ◽  
pp. 2722-2741 ◽  
Author(s):  
Qiaohao Zhu ◽  
KC Carriere
Keyword(s):  
Normal Distribution ◽  
Publication Bias ◽  
Random Effects ◽  
Effect Size ◽  
Meta Analysis ◽  
Truncated Normal Distribution ◽  
Random Effects Models ◽  
Funnel Plot ◽  
Fixed And Random Effects ◽  
Truncated Normal

Publication bias can significantly limit the validity of meta-analysis when trying to draw conclusion about a research question from independent studies. Most research on detection and correction for publication bias in meta-analysis focus mainly on funnel plot-based methodologies or selection models. In this paper, we formulate publication bias as a truncated distribution problem, and propose new parametric solutions. We develop methodologies of estimating the underlying overall effect size and the severity of publication bias. We distinguish the two major situations, in which publication bias may be induced by: (1) small effect size or (2) large p-value. We consider both fixed and random effects models, and derive estimators for the overall mean and the truncation proportion. These estimators will be obtained using maximum likelihood estimation and method of moments under fixed- and random-effects models, respectively. We carried out extensive simulation studies to evaluate the performance of our methodology, and to compare with the non-parametric Trim and Fill method based on funnel plot. We find that our methods based on truncated normal distribution perform consistently well, both in detecting and correcting publication bias under various situations.

scholarly journals Cortical Bone Trajectory Screw Fixation of Lumbar Spine in Adult Patients with Degenerative and Traumatic Spine Disorders

QJM ◽  
2020 ◽  
Vol 113 (Supplement_1) ◽  
Author(s):  
A M Elbadrawy ◽  
T M S Elkhateeb ◽  
E M M A Hassan
Keyword(s):  
Lumbar Spine ◽  
Random Effects ◽  
Screw Fixation ◽  
Meta Analysis ◽  
Pedicle Screws ◽  
Fusion Rate ◽  
Random Effects Models ◽  
Fixed And Random Effects ◽  
Spine Disorders ◽  
Lumbar Pedicle

Abstract Background the CBT for placing lumbar pedicle screws is a technique used to improve fixation during instrumented fusion of the lumbar spine. In comparison with traditional trajectory (TT) for pedicle screws, CBT screws (otherwise known as pars screws or cortical screws) have a more medial starting point and are aimed in a medial to lateral, caudal to cranial direction. First reported in 2009 as a method to increase the purchase of lumbar pedicle screws within bone.(1) Aim of the Work to perform a systematic review and meta-analysis to determine whether traditional Pedicles Screw Fixation (PS Fx) or Cortical Bone Trajectory Screw Fixation (CBT Fx); has been successful for the treatment and fixation of lumbar spine in adult patients with degenerative and traumatic spine disorders; and to compare the 2 techniques to identify risk factor for unfavorable outcome through the recent researches about that issue. Methodology this review was done using standard methodology outlined in the Cochrane Handbook and reported the findings in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement guidelines. Results meta-analysis study showed that; Successful fusion rate in fixed and random-effects models were (92.24% respectively); in SP group.Successful fusion rate in fixed and random-effects models were (92.44% respectively); in CBT group.Fixed and random-effects models showed non-significant difference in successful fusion rate; between the 2 groups of studies (p > 0.05). We calculated safety for each technique through post-operative (failed fusion rate). Conclusion Although there were insignificant p-values in the most of the comparative items but the CBT showed lower average of intraoperative blood loss, operation time and higher average of decrease in VAS & increase in ODI, slightly higher fusion rate in comparison with PS. So we recommend, the use of CBT as an acceptable alternative of PS in lumbar spine fixation.

scholarly journals Effects of dutasteride on prostate cancer incidence: A systematic review and meta-analysis

2020 ◽  
Vol 11 (4) ◽  
pp. 7266-7270
Author(s):  
Gyeong-Eun Min ◽  
Haesoo Kim ◽  
Da Eun Lee ◽  
Kisok Kim
Keyword(s):  
Prostate Cancer ◽  
Random Effects ◽  
Fixed Effects ◽  
Meta Analysis ◽  
Adult Males ◽  
Fixed Effects Model ◽  
Random Effects Models ◽  
Benign Prostate Hypertrophy ◽  
Fixed And Random Effects ◽  
Meta Analyses

5-Alpha-reductase inhibitors (5-ARIs) are used in the treatment of benign prostate hypertrophy (BPH). 5-ARIs, such as finasteride and dutasteride, suppress the biosynthesis of dihydrotestosterone (DHT), a precursor of androgen, which is closely related to the incidence of prostate cancer (PCa). A previous meta-analysis demonstrated a relationship between finasteride use and the incidence of PCA. However, there have been no meta-analyses on the relationship between PCa and dutasteride alone. This meta-analysis was performed to examine the prevalence of PCa in adult males taking dutasteride. We searched PubMed for reports regarding PCa risk and dutasteride use. The study was conducted according to the PRISMA guidelines for systematic reviews and meta-analyses. The analytic hierarchy process (AHP) method was used to weight the studies. Odds ratios (ORs), 95% confidence intervals (CIs), and P-values were calculated using fixed- and random-effects models. A total of eight articles were included in the meta-analysis. The overall OR for both the fixed- and random-effects models was 0.669 and the 95% CI for the random-effects model (0.526–0.851; P = 0.006) was wider than that for the fixed effects model (0.548–0.817; P < 0.001). This study confirmed that the incidence of PCa was significantly reduced by taking dutasteride.

scholarly journals Dyslipidaemia and mortality in COVID-19 patients - a meta-analysis

QJM ◽  
2021 ◽  
Author(s):  
Marco Zuin ◽  
Gianluca Rigatelli ◽  
Claudio Bilato ◽  
Carlo Cervellati ◽  
Giovanni Zuliani ◽  
...  
Keyword(s):  
Random Effects ◽  
Mortality Risk ◽  
Meta Analysis ◽  
Random Effect ◽  
Final Analysis ◽  
Short Term ◽  
Random Effects Models ◽  
Pooled Prevalence ◽  
Statistical Heterogeneity ◽  
Trim And Fill

Abstract Objective The prevalence and prognostic implications of pre-existing dyslipidaemia in patients infected by the SARS-CoV-2 remain unclear. To perform a systematic review and meta-analysis of prevalence and mortality risk in COVID-19 patients with pre-existing dyslipidaemia. Methods Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed in abstracting data and assessing validity. We searched MEDLINE and Scopus to locate all the articles published up to January 31, 2021, reporting data on dyslipidaemia among COVID-19 survivors and non-survivors. The pooled prevalence of dyslipidaemia was calculated using a random effects model and presenting the related 95% confidence interval (CI), while the mortality risk was estimated using the Mantel-Haenszel random effects models with odds ratio (OR) and related 95% CI. Statistical heterogeneity was measured using the Higgins I2 statistic. Results Eighteen studies, enrolling 74.132 COVID-19 patients [mean age 70.6 years], met the inclusion criteria and were included in the final analysis. The pooled prevalence of dyslipidaemia was 17.5% of cases (95% CI: 12.3-24.3%, p &lt; 0.0001), with high heterogeneity (I2=98.7%). Pre-existing dyslipidaemia was significantly associated with higher risk of short-term death (OR: 1.69, 95% CI: 1.19-2.41, p = 0.003), with high heterogeneity (I2=88.7%). Due to publication bias, according to the Trim-and-Fill method, the corrected random-effect ORs resulted 1.61, 95% CI 1.13-2.28, p &lt; 0.0001 (one studies trimmed). Conclusions Dyslipidaemia represents a major comorbidity in about 18% of COVID-19 patients but it is associated with a 60% increase of short-term mortality risk.

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.

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