Questions tagged [meta-analysis]

Methods focused on contrasting and combining results from different studies, in the hope of increasing precision and external validity.

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199 views

Reversing the reference category

I am doing a meta-analysis. How can I change the reference category such as in a pooled analysis? Most studies have reported male as the reference group (Female : Male). However in one study the ...
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2answers
2k views

How do I convert $\eta^2$ to Pearson's r?

I am doing a meta-analysis of associations between sets of variables that are essentially all continuous. However, many studies operationalised them at 'lower' levels, and I have (converted to) most ...
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55 views

Effect size for meta-analysis from ANOVA with significant interaction term

For a meta-analysis, I found a study in which the main effect of A on my dependant variable was not significant but the interaction of A and B and the interaction of A, B and C were. I also have only ...
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1answer
31 views

Calculating SMD from posttest only - is this possible?

I am performing a meta-analysis (with 'metafor' R-project) as described by Becker (1988), and I compute the standardized mean change for a treatment and control group. I compute a (standardized) ...
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1answer
44 views

Pooled analysis of studies with only intervention arm

I want to perform a pooled analysis of studies including only a treatment arm, so no proper control groups are available. Studies present data about subjects before the treatment and after treatment, ...
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0answers
51 views

Calculation of I-squared in meta-analysis of diagnostic accuracy

I would like to calculate heterogeneity statistics (Cochran's Q, I-squared) for a meta-analysis of diagnostic accuracy. I successfully used the 'mada' package in R to calculate these statistics, but ...
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1answer
87 views

How to compare fixed effects of linear mixed models

I have two linear mixed models that I ran with the lmer function from the lme4 package. The models are identical except that I ...
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0answers
112 views

Simple Bayesian meta-analysis in R [closed]

Is there a simple way to conduct a Bayesian meta-analysis in R in order to support equivalence between the effects of two study types? E.g., Bayes factors would be perfect. So, for example I have ...
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0answers
34 views

Statistical test to compare two proportions

I am performing a meta-analysis comparing proportions of patients diagnosed with a disease based on 2 different diagnostic criteria. I have collected and pooled proportions rates (patients with a ...
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1answer
31 views

Meta Regression- Average AGe

I want to conduct a meta-regression, using the variable. The studies in my meta-analysis include studies, that compore two indipendent groups. My question: to calculate average age of a study - is it ...
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1answer
49 views

What transformation can I use to enable a relatively unbiased meta-analysis of $\alpha$ reliability?

I want to meta-analyse reliability estimates. For simplicity, assume the reliability estimate in question is Cronbach's $\alpha$ (aka Guttman's $\lambda$-3). Various packages exist to do meta-analyses ...
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1answer
47 views

Meta-Analysis - Calculating SE from given ES

I have the following problem. I am trying to conduct a meta-analysis and I have an effect size estimation of some unpublished studies. Unfortunately, I don't have the Standard Errors for the mentioned ...
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1answer
343 views

Variance–covariance matrix in meta-analysis of variation metafor

I'm conducting a meta-analysis on estimating a gold standard measure from other simpler measures. To determine the error of estimation, I derived the standard deviations of the differences between the ...
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0answers
16 views

Pseudo replicas in meta-analysis [closed]

How do i control pseudo replicas in meta-analysis studies? I know I can randomize samples using Bootstrap for example, but how do I do this? Any clarification will be most welcome!
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0answers
52 views

Correcting for reliability scores for Hedges g

I've received a revise and resubmit on my meta-analysis investigating the effects of a positive psychology intervention on depression and anxiety symptoms. I used Hedges' g as the effect size within a ...
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0answers
31 views

Summary effect size of multiple dependent effect sizes

Problem Statement I am currently conducting a meta-analysis. At the moment, I am just calculating the effect size for each included study (for our purpose we chose the correlation coefficient r). ...
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2answers
3k views

Meta-analysis of proportions

I am conducting a meta-analysis on 20 studies. The outcome of interest in each study is represented by a proportion/percentage. The sample size n is known and is different for each study. I have ...
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0answers
37 views

Can multilevel meta analysis be random-effects model and/or fixed effects model?

I am learning multilevel meta-analysis (or, three-level meta-analysis e.g., https://bookdown.org/MathiasHarrer/...
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1answer
232 views

How to convert beta from logistic regression into cohen's d?

Is there a way to transform a coefficient from a logistic regression into a cohen's d value? I am trying to calculate the cohen's d for a study with a binary DV while controlling for another ...
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85 views

Meta-analyses using raw mean as Effect Size, instead of mean differences (e.g., Cohen's d)

I am writing up my meta-analysis using raw mean scores as effect sizes (i.e., reported mean scores on a certain standardized test) using the metafor package in R. ...
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0answers
38 views

How to convert sampling sampling variances for a meta-analysis using raw means as effect sizes?

I am conducting a meta-analysis using raw mean scores as effect sizes (i.e., reported test scores on a certain standardized test). I found a calculation formula for sampling variances provided by, e....
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0answers
20 views

Trelllis plots in meta-analsysis [closed]

I am trying to plot, a trellis plot. But I get an error and I don't know what its means. ...
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1answer
87 views

What methods could be used to determine the validity of results from meta analysis besides conflict of interest?

Based on the answers I've read to a question1 on the Skeptics stack exchange, I began to wonder what methods besides the declaration of industry funding could be used to determine the validity of ...
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0answers
23 views

Multilevel regression meta-analysis : no existing package? (Edited)

The question is in the title. Meta-analysis with binomial distribution I'm trying to do a meta-analysis on occurence of an event across different studies. For each study $i$ ($i=1,\dots,N$), I have ...
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1answer
181 views

Backward model selection in metanalysis using 'glmulti' and/or 'metafor'

I want to test with a full model testing significant interactions with the main predictor 'Nadd' for my log transformed response ratio (...
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0answers
13 views

How do I use clinical trials as random effects in a cox regression model stratified according to trial for an individual patient data meta-analysis? [closed]

I am performing an individual patient data meta-analysis and pooling several trials. I have the data all combined in a single data set and want to fit it in a Cox regression model stratified according ...
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1answer
34 views

Prediction Intervals by meta package

I am using meta 4.9-5 package for conducting meta-analysis on correlation data. But I cannot figure out why it is unable to calculate lower and upper prediction intervals even I have set prediction = ...
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1answer
65 views

How to handle studies that don’t provide an estimate of effect size in a meta-analysis?

Say we want to survey the literature to find out the effect of Treatment A on Value B. Some studies provide an effect size estimate with confidence intervals and t-test results (e.g., “Treatment A ...
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2answers
275 views

Meta-Analysis on Effect Sizes with 95% Bayesian CI from CausalImpact R package

I am using the CausalImpact package in R to calculate the impact of a marketing intervention using Bayesian Structural Time Series. This methodology and package is explained in Broderson et al. 2015 ...
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2answers
174 views

Are there good alternatives to Cochran's Q test for heterogeneity in meta-analysis?

We used the Q test to determine heterogeneity with p-values <0.10. A highly recognised statistician commented that the Q test has low power and that it should not be used to determine presence of ...
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2answers
916 views

What does the p value mean in meta analysis results output?

What does the p value mean in a meta analysis results output? My meta analysis is looking at the proportion of people affected by PTSD. I am using the software OpenMeta Analyst which runs r in the ...
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2answers
2k views

Is precision-based (i.e. inverse-variance) weighting integral to meta-analysis?

Is precision-based weighting central to meta-analysis? Borenstein et al. (2009) write that for meta-analysis to be possible all that is necessary is that: Studies report a point estimate which can ...
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2answers
338 views

Meta-analysis and homogeneity — what did these guys do?

I appreciate any insight into this meta-analysis. This is a meta-analysis on alogliptin efficacy and safety. In the 2nd paragraph of the discussion that make this statement: Although heterogeneity ...
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1answer
109 views

Heterogeneity measures when pooling meta-analyses: what assumptions do we make?

I am looking at the possibilities and limitations of meta-meta-analysis (MMA), put differently, pooling the results of multiple meta-analysis. I realise that it is better to include primary studies, ...
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1answer
32 views

Regression multi-level meta-analysis with binomial data in R: no existing package? [closed]

The question is in the title. Meta-analysis with binomial distribution I'm trying to do a meta-analysis on occurence of an event across different studies. For each study $i$ ($i=1,\dots,N$), I have ...
11
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2answers
1k views

Can I include an effect size as an independent variable in a meta-regression?

My question is whether I can use an effect size $X$ as a dependent variable and another effect size $Y$ as the independent variable in a meta-regression? For example, I conducted a meta-analysis for ...
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3answers
65 views

Is it worth doing (single-armed) meta analysis if the studies' heterogeneity is very large?

I'm currently trying to perform a single-armed meta analysis of immunotherapy on breast cancer, which I believe this meta analysis will be the first among its intervention and cancer subtype. The ...
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0answers
37 views

Predicting disease based on eeg electrode power features and source power estimates

The dataset consists of Eeg electrode power features in all power bands(alpha, beta, delta..both relative and absolute) and source power features (obtained after source estimation) in addition to ...
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0answers
48 views

Why is Metafor R package giving an I2 for fixed effects meta-analysis model (rma.uni)? [closed]

I'm trying to run a fixed effects meta-analysis using the Metafor R package and in the documentation I read that it does not return an I^2 for fixed effects models, only for random effects models. ...
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2answers
3k views

How to use Stata to pool Cohen's d? [closed]

I am attempting to calculate Cohen's d and then pool those estimates into a summary effect size. Can anyone help? (Stata or SPSS software owned).
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1answer
46 views

Help with meta-regression

I want to implement a meta-regression and require some assistance. Suppose that two univariate features ($X$ and $Y$) were measured from two samples $A$ and $B$ of size $N_A$ and $N_B$, respectively. ...
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1answer
47 views

What's the statistical method of comparing the amount of pre-post difference scores of between groups?

I am currentnly doing a meta-analysis of the effects of social cognitive training on social cognitive function of patients of schizophrenia. There are wo conditions: treatment group receving social ...
3
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1answer
81 views

Meta-analysis with random effects on prevalence data with > 2 possible outcomes: is it necessary that the weighted prevalences all add up to 100?

I am running a meta analysis on prevalence data. Participants can belong to one of four groups. Each study produces the percentage of participants that belong to each group (e.g., Group A: 50%; Group ...
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1answer
53 views

model test p-value>0.05 but intrcpt <0.05 [closed]

Mixed-Effects Model (k = 21; tau^2 estimator: SJ) tau^2 (estimated amount of residual heterogeneity): 0.2301 (SE = 0.0752) tau (square root of estimated tau^2 value): 0.4797 I^2 (...
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1answer
180 views

How to deal with unexpected low heterogeneity in meta-analysis?

I am performing a meta-analysis in R with metafor package. Primary studies report the reduction of plant species to certain amount of nitrogen fertilization. Effect ...
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0answers
35 views

Assembling meta-analysis data with paired data for metafor

I am trying to assemble a meta-analytic dataset for computing yi and vi for metafor. For this dataset, I am including paired data (i.e., one sample of participants that completed upright and inverted ...
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1answer
47 views

interpreting meta regression results in R

I performed meta-regression in R and got the following results: Mixed-Effects Model (k = 21; tau^2 estimator: ML) ...
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1answer
39 views

SMD meta-analysis including cluster-randomised trials: is it possible? If so, how?

Where we have cluster-adjusted results from trials (summary statistics), under what circumstances can we include them in a standardised mean difference (SMD) meta-analysis and which calculations are ...
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0answers
32 views

Covariance structure of effects in multivariate meta-analysis with correlated outcomes and predictors

I'm working on a meta-analysis of studies examining the correlation between SES and mental health. Unfortunately, studies typically have multiple measures of both SES and mental health, which I've ...

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