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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1answer
15 views

Combining effect sizes to learn about the difference between two groups?

I am interesting in learning if there is difference between the control and the treatment group in a paper I am reading. Unfortunately the paper only compares the respective conditions to a 0 effect ...
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1answer
25 views

Meta Analysis with Likelihood Ratios

I am currently writing a protocol for a systematic review and meta analysis to analyze the available evidence regarding epidemiologic studies on risk factors for pneumonia. The end goal of the ...
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0answers
14 views

How to find standard error or standard deviation of the percent difference between two prevalence values?

I am having trouble working out how to find the standard error or standard deviation for a column that contains the percentage points difference for two prevalence values. I have general practice ...
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1answer
21 views

How does pooling affect variance?

Suppose you are looking at the prevalence of a certain disease and you can detect this disease in fecal samples. How does having a bunch of pooled fecal samples (i.e., taking a fecal sample from 5 ...
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28 views

Meta-Analysis without a Control Group

I am conducting a systematic review and meta-analysis which is investigating health-related quality of life in a particular patient population. I am having difficulties with conducting the meta-...
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0answers
37 views

Why is my meta analysis OR and 95% CI less precise than my study results? [closed]

I am trying to perform a simple weighted average meta analysis of 2 odds ratios from 2 studies (I will be adding more studies when I get the results). However, when I meta analyse using the METAFOR ...
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1answer
27 views

Should we do a meta-analysis of non-inferiority trials?

Since non-inferiority trials are designed meticulously to achieve an effect size demonstrating no significant difference between treatments, so there may be certain essential differences in design of ...
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10 views

Transforming reported effects at sample means for a meta-analysis

I'm doing a meta-analysis about tax avoidance (like this: https://poseidon01.ssrn.com/delivery.php?ID=...
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23 views

How to Calculate Observed Variance in a Random-Effects Meta-Analysis

I've received a revise and resubmit on a meta-analysis investigating the effects of a positive psychology intervention on depression and anxiety symptoms. I used Hedges' g as the effect size with a ...
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1answer
23 views

Data fusion for multiple correlated t-tests

Question is similar to this unanswered question. I have several data sets each corresponding to a different location. Every row of each dataset contains a measurement of the same quantity taken at a ...
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0answers
9 views

How do I test whether the distribution of effect sizes are different across intervention types?

I've extracted 3,456 Cohen's d effect sizes from published studies, and categorized each based on intervention type (four different intervention types). I did this to understand the distribution of ...
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0answers
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Possible NAs in Beslow estimation with repeated data?

I would like to seek your advice on a problem I encountered recently. I bootstrap on a test that includes a Breslow estimate for survival data. Since these are meta-analyzes, I am bootstrapping on ...
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0answers
25 views

How to bootstrap a statistic calculed in a meta-analyis?

I have calculated a statistic in a meta-analysis of individual data and I want to bootstrap it to obtain the variance (no analytic expression is available) to make a test. First, I was naively ...
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33 views

Meta-analysis with pre-weighted data

does anyone know of any references that speak about whether studies can be included in a meta-analysis if the study is already given some kind of weighting factor? For example, large scale survey ...
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46 views

What is the formula for combining Hedges' g across studies?

If I have Hedges g for a bunch of different studies, what is the formula for combining them? EDIT with more detail. This is part of a meta-analysis. Each study was small, with N usually equal 6 or 8 ...
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1answer
25 views

'rma.mv' function output- fisher Z or raw correlation

I would like to ask a question regarding the output of the rma.mv function. I had raw correlations which I transformed into Fisher's Z correlations using the 'escalc' function. Then, I performed a ...
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Is the shrinkage of subgroup analyses in meta-analysis an example of Stein's paradox?

This paper writes (edited for concision): Consider, a doctor in Germany confronted by a meta-analysis of long term‚ $\beta$ blockade after myocardial infarction. Although a robust beneficial effect ...
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0answers
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Selecting the correct clustering variable when calculating robust meta-analytic tests and error terms for dependent data [closed]

Background I am revising a meta-analysis for publication and have been asked to adopt a multivariate modelling approach using the rma.mv and robust functions within the metafor package in R. ...
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34 views

Pseudoreplication in studies used in meta-analysis (problem with sample size)

We are conducting a meta-analysis, but we have problems with pseudoreplication within our primary studies. Most of the studies use correlation analysis (but we also have linear regression and GLMM) ...
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1answer
46 views

Different results meta vs metafor

I'm running a meta-analysis of single proportions. I know this can be done in both meta and metafor but I am getting slightly different results using both the moment I add in smaller studies. Suppose ...
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1answer
30 views

Analysis of pre and post treatment

I have the following data: A random group of patients with a certain disease who receive a drug at a certain time. Dose of the drug given to the patient. This drug has an affect to the heart which ...
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0answers
16 views

How to calculate mean (SD) from different values for a meta-analysis

For a "meta-analysis" i would like to sum up the result from 6 studies. Still values stated in these studies are median (IQR), mean (SD), mean (range), mean (95% CI). Do I have a chance to calculate a ...
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26 views

How to manage publication bias

my team has been carrying out a meta-analysis study. Through the process, who have statistically detected publication bias, according to Egger's regression test; to consider the suppressed studies to ...
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18 views

best subset of moderators for meta-analysis in R

I have a large number of "categorical" moderators (35 moderators). I am planning to use the best subset of these moderators that can maximally explain the variation in my 257 correlated effect sizes ...
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1answer
37 views

Meta-Analysis: Effect size calculation - p-value

Is it possible to calculate an effect size if only a p-value and sample sizes of two independet groups are given? Kind regards Joanne
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1answer
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Meta-analysis for complex data with many treatments (and often no controls)?

I'm planning to conduct a meta-analysis of the catches of invertebrates from various types of sampling methods - with the question of: 'which method catches the most inverts?' In a preliminary ...
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1answer
161 views

Why do we log transform response ratios?

In meta-analysis, it seems a standard practice to take the natural log of the response ratio before evaluating it. My question is why? That is, if I have a treatment mean (Xe) and a control mean of ...
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1answer
25 views

P-Uniform* interpretation

I have a question concering the interpretation of my p-uniform* results. So this is my results: Estimating effect size p-uniform* ...
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1answer
21 views

Controlling for baseline differences?

I am comparing two groups, with data before and after retirement, to see the effect retirement has on depression levels. The control group works over the two measurement points, and the retirees ...
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22 views

To pool or combine multiple correlations: Pearson and ICC

For part of a study we are running, we are investigating the correlation between a post-practice score, and the subsequent day's pre-practice score. We are looking at the potential association between ...
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1answer
43 views

Meta - Analysis - Effect size calculation

I am trying to include a study into my meta-analysis, that reports results of an ANOVA: F(1,76) = 11.23, p = 0.001, n²=0,13 My question is how to calculate Hedge g from this data? I work with R, using ...
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20 views

Fixed vs. Random effects meta- regression [closed]

how to understand the differences between fixed vs. random effects meta-regression? Not meta-analysis.
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51 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
29 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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33 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
61 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
31 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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0answers
71 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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1answer
28 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
45 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
42 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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0answers
15 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
50 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 ...
1
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0answers
26 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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0answers
33 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
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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1answer
137 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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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
69 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
18 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. ...