Shortcomings of an approximate confidence interval for moment-based estimators of the between-study variance in random-effects meta-analysis

2016 ◽  
Vol 7 (4) ◽  
pp. 459-461 ◽  
Author(s):  
David C. Hoaglin
Keyword(s):  
Confidence Interval ◽  
Random Effects ◽  
Meta Analysis ◽  
Approximate Confidence Interval

scholarly journals Health-Related Quality of Life in Athletes: A Systematic Review With Meta-Analysis

2016 ◽  
Vol 51 (6) ◽  
pp. 442-453 ◽  
Author(s):  
Megan N. Houston ◽  
Matthew C. Hoch ◽  
Johanna M. Hoch
Keyword(s):  
Quality Of Life ◽  
Confidence Interval ◽  
Random Effects ◽  
Meta Analysis ◽  
Collegiate Athletes ◽  
Health Related Quality ◽  
Related Quality ◽  
Health Related ◽  
History Of

Context: Assessment of health-related quality of life (HRQOL) after injury is important. Differences in HRQOL between nonathletes and athletes and between injured and uninjured athletes have been demonstrated; however, the evidence has not been synthesized. Objective: To answer the following questions: (1) Does HRQOL differ among adolescent and collegiate athletes and nonathletes? (2) Does HRQOL differ between injured adolescent and collegiate athletes or between athletes with a history of injury and uninjured athletes or those without a history of injury? Data Sources: We systematically searched CINAHL, MEDLINE, SPORTDiscus, and PubMed. A hand search of references was also conducted. Study Selection: Studies were included if they used generic instruments to compare HRQOL outcomes between athletes and nonathletes and between uninjured and injured athletes. Studies were excluded if they did not use a generic instrument, pertained to instrument development, or included retired athletes or athletes with a chronic disease. Data Extraction: We assessed study quality using the modified Downs and Black Index Tool. Bias-corrected Hedges g effect sizes and 95% confidence intervals (CIs) were calculated. The Strength of Recommendation Taxonomy (SORT) was used to determine the overall strength of the recommendation. A random-effects meta-analysis was performed for all studies using the composite or total score. Data Synthesis: Eight studies with modified Downs and Black scores ranging from 70.6% to 88.4% were included. For question 1, the overall random-effects meta-analysis was weak (effect size = 0.27, 95% confidence interval = 0.14, 0.40; P < .001). For question 2, the overall random-effects meta-analysis was moderate (effect size = 0.68, 95% confidence interval = 0.42, 0.95; P < .001). Conclusions: Grade A evidence indicates that athletes reported better HRQOL than nonathletes and that uninjured athletes reported better HRQOL than injured athletes. However, the overall effect for question 1 was weak, suggesting that the differences between athletes and nonathletes may not be clinically meaningful. Clinicians should monitor HRQOL after injury to ensure that all dimensions of health are appropriately treated.

scholarly journals 325The incidence of primary postpartum haemorrhage following in-hospital birth: a systematic review and meta-analysis

2021 ◽  
Vol 50 (Supplement_1) ◽  
Author(s):  
Bewket Tadesse Tiruneh ◽  
Gayle McLelland ◽  
Virginia Plummer
Keyword(s):  
Systematic Review ◽  
Confidence Interval ◽  
Random Effects ◽  
Postpartum Haemorrhage ◽  
Meta Analysis ◽  
Random Effects Model ◽  
Preventive Strategies ◽  
Heterogeneity Test ◽  
Ovid Medline ◽  
Hospital Births

Abstract Background Although primary postpartum haemorrhage is a leading cause of maternal mortality, in the wider literature, there is inconsistent results in studies about its incidence. This study was designed to determine the pooled incidence of primary postpartum haemorrhage among women following in-hospital births. Methods This review used a systematic review and meta-analysis approach. We systematically searched electronic databases of Ovid MEDLINE, Ovid Emcare, Embase, PsycINFO, and CINAHL. Studies reporting the incidence of primary postpartum haemorrhage following in-hospital births were included. The pooled incidence of primary postpartum haemorrhage with a 95% confidence interval was calculated using random-effects model. Heterogeneity test between studies, and publication bias were assessed with I-square statistics and Egger’s test respectively. Results Ten of the 1548 studies were found to be eligible and were included in this systematic review and meta-analysis. The pooled incidence of primary postpartum haemorrhage following in-hospital births was nearly 12% (95% CI: 7.74- 17.61), with no evidence of between studies heterogeneity. Conclusions The incidence of primary postpartum haemorrhage following in-hospital births was high, and suggest that preventive strategies implemented to reduce its occurrence needs further strengthening using training. Key messages The result of this review suggests that globally at least one in ten women experience a primary postpartum haemorrhage following in-hospital births. This is higher than anticipated. The application of the recommended strategies for the prevention of primary postpartum haemorrhage should be re-emphasized.

Bias and Precision of Alternate Estimators in Meta-Analysis: Benefits of Blending Schmidt-Hunter and Hedges Approaches

2017 ◽  
Vol 22 (2) ◽  
pp. 490-514 ◽  
Author(s):  
Michael T. Brannick ◽  
Sean M. Potter ◽  
Bryan Benitez ◽  
Scott B. Morris
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Confidence Interval ◽  
Root Mean Square Error ◽  
Random Effects ◽  
Meta Analysis ◽  
Size Distributions ◽  
Mean Square ◽  
The Mean

We describe a new estimator (labeled Morris) for meta-analysis. The Morris estimator combines elements of both the Schmidt-Hunter and Hedges estimators. The new estimator is compared to (a) the Schmidt-Hunter estimator, (b) the Schmidt-Hunter estimator with variance correction for the number of studies (“ k correction”), (c) the Hedges random-effects estimator, and (d) the Bonett unit weights estimator in a Monte Carlo simulation. The simulation was designed to represent realistic conditions faced by researchers, including population random-effects distributions, numbers of studies, and skewed sample size distributions. The simulation was used to evaluate the estimators with respect to bias, coverage of the 95% confidence interval of the mean, and root mean square error of estimates of the population mean. We also evaluated the quality of credibility intervals. Overall, the new estimator provides better coverage and slightly better credibility values than other commonly used methods. Thus it has advantages of both commonly used approaches without the apparent disadvantages. The new estimator can be implemented easily with existing software; software used in the study is available online, and an example is included in the appendix in the Supplemental Material available online.

scholarly journals The Diamond Ratio: A Visual Indicator of the Extent of Heterogeneity in Meta-Analysis

2020 ◽  
Author(s):  
Maxwell Cairns ◽  
Geoff Cumming ◽  
Robert Calin-Jageman ◽  
Luke A. Prendergast
Keyword(s):  
Confidence Interval ◽  
Random Effects ◽  
Meta Analysis ◽  
Fixed Effect ◽  
Forest Plot ◽  
Summary Measure ◽  
First Time

The result of a meta-analysis is conventionally pictured in the forest plot as a diamond, whose length is the 95% confidence interval (CI) for the summary measure of interest. The Diamond Ratio (DR) is the ratio of the length of the diamond given by a random effects meta-analysis to that given by a fixed effect meta-analysis. The DR is a simple visual indicator of the extent of heterogeneity in the meta-analysis, where increasing values of DR greater than 1.0 indicate increasing heterogeneity. We investigate the properties of the DR, and its relationship to four conventional but more complex measures of heterogeneity. We propose for the first time a CI on the DR, and show that it performs well in terms of coverage. We provide example code to calculate the DR and its CI, and to show these in a forest plot. We conclude that the DR is a useful indicator that can assist students and researchers to understand heterogeneity, and to appreciate its extent in particular cases.

IL-17A in COVID-19 Cases: a meta-analysis

2021 ◽  
Vol 15 (11) ◽  
pp. 1630-1639
Author(s):  
Sukayna Fadlallah ◽  
Marcel S Sham Eddin ◽  
Elias A Rahal
Keyword(s):  
Autoimmune Disease ◽  
Severe Acute Respiratory Syndrome ◽  
Confidence Interval ◽  
Random Effects ◽  
Proinflammatory Cytokine ◽  
Meta Analysis ◽  
Random Effects Model ◽  
Weighted Mean ◽  
Disease Pathogenesis ◽  
Mean Differences

Introduction: Numerous reviews, commentaries and opinion pieces have suggested targeting IL-17A as part of managing Coronavirus disease 2019 (COVID-19), the notorious pandemic caused by the Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). IL-17A is a proinflammatory cytokine attributed with homeostatic roles but that is also involved in autoimmune disease pathogenesis. While some studies have reported an increase in IL-17A in COVID-19 cases, no significant associations were found by others. Hence, we undertook this meta-analysis to study serum IL-17A levels in COVID-19 patients in relation to disease severity. Methodology: Multiple databases were systematically reviewed for literature published on the topic from January 1, 2019 to April 30, 2021. A random effects model was used to calculate weighted mean differences (WMDs) and 95% confidence interval (CIs) as well as the

Clinical presentations and outcomes of Takotsubo syndrome in the setting of subarachnoid hemorrhage: A systematic review and meta-analysis

2016 ◽  
Vol 7 (3) ◽  
pp. 236-245 ◽  
Author(s):  
Akram Y Elgendy ◽  
Islam Y Elgendy ◽  
Hend Mansoor ◽  
Ahmed N Mahmoud
Keyword(s):  
Systematic Review ◽  
Subarachnoid Hemorrhage ◽  
Confidence Interval ◽  
Hospital Mortality ◽  
Random Effects ◽  
Odds Ratio ◽  
Fixed Effects ◽  
Meta Analysis ◽  
Takotsubo Syndrome ◽  
Spontaneous Subarachnoid Hemorrhage

Background: Evidence remains inconsistent regarding the incidence and prognosis of Takotsubo syndrome in the setting of subarachnoid hemorrhage. Thus, we aimed to evaluate the clinical presentation and in-hospital mortality of these patients. Methods: A systematic review of the electronic databases was conducted for studies involving patients with spontaneous subarachnoid hemorrhage and concomitant findings of classical Takotsubo syndrome on transthoracic echocardiogram. A meta-analysis was conducted for the primary outcome of in-hospital mortality using the Mantel–Haenszel method for fixed effects and the DerSimonian and Laird method for random effects, with 95% confidence interval and a p-value <0.05 for statistical significance. Results: Ten studies were retrieved with a total of 157 patients presenting with classical Takotsubo syndrome, representing 4.4% of the subarachnoid hemorrhage total population. The overall incidence of in-hospital mortality was 30% in the patients who developed Takotsubo syndrome. Meta-analysis illustrated a significant increase in the odds of in-hospital mortality for the Takotsubo syndrome patients by fixed effects model (odds ratio 2.6, 95% confidence interval 1.16–5.85, p=0.02, I2=39%), with a trend towards increased risk of in-hospital mortality by random effects model (odds ratio 3.00, 95% confidence interval 0.90–9.77, p = 0.07). Conclusions: The incidence of Takotsubo syndrome in patients with spontaneous subarachnoid hemorrhage seems to be high with a trend towards higher risk of in-hospital mortality in those patients. Thus, patients presenting with subarachnoid hemorrhage might benefit from a comprehensive cardiac evaluation upon presentation for early detection and proper triage of this high-risk population.

scholarly journals Registered Replication Report on Srull and Wyer (1979)

2018 ◽  
Vol 1 (3) ◽  
pp. 321-336 ◽  
Author(s):  
Randy J. McCarthy ◽  
John J. Skowronski ◽  
Bruno Verschuere ◽  
Ewout H. Meijer ◽  
Ariane Jim ◽  
...  
Keyword(s):  
Confidence Interval ◽  
Personality Traits ◽  
Random Effects ◽  
Priming Effect ◽  
Meta Analysis ◽  
Total Sample

Srull and Wyer (1979) demonstrated that exposing participants to more hostility-related stimuli caused them subsequently to interpret ambiguous behaviors as more hostile. In their Experiment 1, participants descrambled sets of words to form sentences. In one condition, 80% of the descrambled sentences described hostile behaviors, and in another condition, 20% described hostile behaviors. Following the descrambling task, all participants read a vignette about a man named Donald who behaved in an ambiguously hostile manner and then rated him on a set of personality traits. Next, participants rated the hostility of various ambiguously hostile behaviors (all ratings on scales from 0 to 10). Participants who descrambled mostly hostile sentences rated Donald and the ambiguous behaviors as approximately 3 scale points more hostile than did those who descrambled mostly neutral sentences. This Registered Replication Report describes the results of 26 independent replications ( N = 7,373 in the total sample; k = 22 labs and N = 5,610 in the primary analyses) of Srull and Wyer’s Experiment 1, each of which followed a preregistered and vetted protocol. A random-effects meta-analysis showed that the protagonist was seen as 0.08 scale points more hostile when participants were primed with 80% hostile sentences than when they were primed with 20% hostile sentences (95% confidence interval, CI = [0.004, 0.16]). The ambiguously hostile behaviors were seen as 0.08 points less hostile when participants were primed with 80% hostile sentences than when they were primed with 20% hostile sentences (95% CI = [−0.18, 0.01]). Although the confidence interval for one outcome excluded zero and the observed effect was in the predicted direction, these results suggest that the currently used methods do not produce an assimilative priming effect that is practically and routinely detectable.

Exploring the Relationships Between Problem Gambling and ADHD: A Meta-Analysis

2016 ◽  
Vol 23 (12) ◽  
pp. 1427-1437 ◽  
Author(s):  
Jennifer Theule ◽  
Kylee E. Hurl ◽  
Kristene Cheung ◽  
Michelle Ward ◽  
Brenna Henrikson
Keyword(s):  
Confidence Interval ◽  
Problem Gambling ◽  
Random Effects ◽  
Meta Analysis ◽  
Random Effects Model ◽  
Adhd Symptoms ◽  
Weighted Mean ◽  
Problem Gamblers ◽  
Gambling Severity ◽  
Meta Analyses

Objective: At present, there are inconsistencies in the literature pertaining to the association between ADHD and problem gambling. This study utilized meta-analytic techniques to clarify the association between symptoms of problem gambling and symptoms of ADHD. Method: Several meta-analyses were conducted using a random effects model. PsycINFO, PubMed, ProQuest Dissertations & Theses, and Google Scholar were searched for relevant studies. Results: The weighted mean correlation between ADHD symptomology and gambling severity was r = .17, 95% confidence interval (CI) = [0.12, 0.22], p < .001. Mean age of the sample was the only moderator to approach significance, with greater age being linked to a stronger relationship between symptoms of ADHD and gambling severity. Conclusion: Clinicians needs to be cognizant of the greater risk of ADHD symptoms when working with problem gamblers and vice versa.

Staphylococcus aureus Colonization before Infection Is Not Associated with Mortality among S. aureus-infected Patients: A Meta-analysis

2012 ◽  
Vol 33 (8) ◽  
pp. 796-802 ◽  
Author(s):  
Marin L. Schweizer ◽  
Ann Bossen ◽  
Jennifer S. McDanel ◽  
Leslie K. Dennis
Keyword(s):  
Staphylococcus Aureus ◽  
Confidence Interval ◽  
Random Effects ◽  
Meta Analysis ◽  
Attributable Mortality ◽  
Prior History ◽  
Random Effects Model ◽  
Risk Of Mortality ◽  
Increased Risk ◽  
History Of

Background and Objective.The literature is conflicted as to whether people colonized with Staphylococcus aureus are at an increased risk of mortality. The aim of this meta-analysis was to review and analyze the current literature to determine whether prior history of S. aureus colonization is associated with mortality among S. aureus-infected patients.Methods.The PUBMED databases were searched with keywords related to S. aureus colonization and mortality. After reviewing 380 article abstracts and 59 articles in detail, only 7 studies had data on the association between S. aureus colonization and mortality among S. aureus-infected patients. Crude estimates of study odds ratios (ORs) were calculated on the basis of data from subset analyses. We pooled crude ORs from the 7 studies using a random-effects model. Woolf's test for heterogeneity was assessed.Results.When all studies were pooled in a random-effects model, no association between S. aureus colonization and mortality among S. aureus-infected patients was seen (pooled OR, 1.08 [95% confidence interval (CI), 0.32–3.66]; n = 7; heterogeneity P = .05). When the analyses were restricted to infection-attributable mortality, the association between colonization and mortality among S. aureus-infected patients was not statistically significant (pooled OR, 0.42 [95% CI, 0.15–1.21]; n = 4; heterogeneity P = .28).Conclusions.S. aureus colonization was not associated with mortality among patients who developed an S. aureus infection. Interventions to decolonize S. aureus carriers may prevent S. aureus infections but may not be sufficient to prevent mortality.

Glutathione S-transferase M1, T1, and P1 Polymorphisms and Ovarian Cancer Risk: A Meta-Analysis

2010 ◽  
Vol 20 (5) ◽  
pp. 732-737 ◽  
Author(s):  
Konstantinos P. Economopoulos ◽  
Theodoros N. Sergentanis ◽  
Nikos F. Vlahos
Keyword(s):  
Ovarian Cancer ◽  
Cancer Risk ◽  
Confidence Interval ◽  
Random Effects ◽  
Fixed Effects ◽  
Meta Analysis ◽  
Ovarian Cancer Risk ◽  
Case Control Studies ◽  
Increased Risk ◽  
Gstp1 Ile105val

Introduction:Cytosolic glutathione S-transferase (GST) comprises multiple isoenzymes that catalyze reactions between glutathione and lipophilic compounds with electrophilic centers, resulting in the neutralization of toxic compounds, xenobiotics, and products of oxidative stress. Several studies have examined whether GST polymorphisms (GSTM1 null/present genotype, GSTT1 null/present genotype, and GSTP1 Ile105Val) represent risk factors for ovarian cancer, as they all may denote reduced enzyme activity. This meta-analysis aimed to examine the associations between the aforementioned polymorphisms and ovarian cancer risk.Methods:The MEDLINE database was searched up to September 2009 using the appropriate terms. Case-control studies with no mutually overlapping populations were selected. Pooled odds ratios (ORs) were appropriately derived from fixed-effects or random-effects models. Meta-regression with publication year was also performed.Results:Eight studies regarding GSTM1 null polymorphism status (2357 cases and 3044 controls), 6 studies concerning GSTT1 null polymorphism (1923 cases and 2759 controls), and 3 studies on GSTP1 Ile105Val were included in the meta-analysis. The GSTM1 null genotype was not associated with an increased risk for ovarian cancer (pooled OR, 1.031; 95% confidence interval, 0.867-1.226; random effects). The GSTT1 null genotype was not associated with an increased ovarian cancer risk (pooled OR, 0.934; 95% confidence interval, 0.804-1.086; random effects); similarly, no significant associations were demonstrated for GSTP1 Ile105Val.Conclusions:The examined GSTM1, GSTT1, and GSTP1 genotype polymorphisms do not seem to confer any additional risk for ovarian cancer. Given that the studies included in this meta-analysis involve mainly white populations, these results cannot be extrapolated on other populations, and additional data are needed for future race-specific analyses.

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