Meta-analysis refers to methods focused on contrasting and combining results from different studies, in the hope of increasing precision and external validity, as well as identifying patterns among study results, sources of disagreement, or other interesting relationships that may come to light in ...

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Discrepancy between metafor (rma.mv) and metaSEM (meta3) estimates for multilevel meta-analysis

I'm wondering why I get slightly different estimates for a meta-analyzed set of effect sizes, when using the rma.mv function from the metafor package, compared to the meta3 function from the metaSEM ...
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19 views

Identifying statistically significant categorical variables with rma.mv

I'm running a meta-regression/multi-level analysis that contains only categorical variables. The printout of the data is as follows: res.fe ...
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21 views

How do I test whether means are equal when I have summary stats for 2 samples from one population and for 1 sample from a second? [duplicate]

I think this is a "meta-analysis" situation. I've got 3 samples (from 3 studies); I've assumed that two are from population A (treatment A) and one is from population B (treatment B). I have the ...
3
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1answer
34 views

Model selection/multi-level model with metafor package

I'm attempting to conduct both a model selection and multilevel model analysis with the metafor package. Unfortunately, the data I am working with does not have any control group, only a response rate(...
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11 views
+50

Is there any meaningfully robust approach to conduct a network meta-analysis of diagnostic test accuracy studies?

I am working on a systematic review including several imaging modalities for coronary artery disease, but the evidence network is quite large, including different modalities, often compared one to the ...
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1answer
45 views

Which of the several measures of d-statistics is better for a meta-analysis of effect-sizes?

Several measures including Cohen's d are available for computing d-statistics. It is difficult to choose one of them for a meta-analysis? Are there any guidelines ?
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1answer
59 views

Multiple comparisons when examining the results of unrelated trials

Imagine that you have a data set that is like the one below. (The data is all made up and is not specific to the problem.) ...
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1answer
43 views

Corrected intercorrelations knowing sample size and variable reliabilities

I have a list of studies from a meta-analysis. The studies list the correlations between two variables (scales, and their reliabilities - alphas), and the N. I am looking to make these correlations ...
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1answer
84 views

Independent measures for pre-post data

In conducting a meta-analysis, I have pre-post data from single case designs. Unfortunately, I do not have access to the correlations between the pre and post scores. Is it correct that if I ...
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37 views

Combining data in the same study

I have identified 17 studies for use in a meta-analysis. In order to make sure that I analyze the data correctly, I had a couple of questions regarding how to approach two of them. First, one ...
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0answers
30 views

Intuition behind why moderator meta-analysis differs from separate analyses

I'm trying to understand the intuition behind the estimates I get from a single two-level meta-analysis with a moderator compared to separate two-level meta-analyses for each moderator value. My ...
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1answer
21 views

Within subject effect size when no correlation available

I am doing a research project on the topic of replicability in psychology. To do this, I did a set of 10 meta-analysis on different studies. My problem is the following : some of those studies were ...
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1answer
30 views

Forest Plot: Proportions on x axis

In most descriptions of Forest Plots the x-axis is an Odds Ratio or a Difference of means etc. But I'm now reading a paper where the x-axis is labeled "Proportion" with the scale going from 0 to 0.8. ...
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193 views

Making a Bayesian prior from a frequentist result

How should one go about turning a frequentist result into a Bayesian prior? Consider the following pretty generic scenario: An experiment was conducted in the past and a result on some parameter $\...
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1answer
25 views

Estimating dependent t-test for paired samples when only means and SDs are available

I'm attempting to extract t-values from a series of published papers for a meta-analysis. The specific measure of interest is the difference in performance (proportion correct on a memory test) ...
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26 views

Cohen's d in pre-post meta analysis based on means and SD

As follow up on this question:I want to incooporate studies using different continues outcome in a meta analysis using SMD. I am following this guide and I do not fully understand how to calculate the ...
2
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1answer
28 views

'moderator' analyses in a meta-analysis

Sorry if I use the wrong terms here, I am still learning how to do this. I am conducting an meta-analysis comparing two treatment types, using Cohen's d. I have completed the primary analyses of the ...
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22 views

Bootstrap in meta-analysis

I am conducting a network meta-analysis of clinical trials on cardioprotective drugs in patients undergoing chemotherapy (see PROSPERO protocol CRD42015029915), and I was wondering whether it would ...
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1answer
34 views

How to treat cohen's d Infinites/NaNs calculated using binary proportions for metanalysis

I am trying to do a metanalysis (using Wilson meta-analysis http://mason.gmu.edu/~dwilsonb/ma.html) comparing the dropout percentage of a treatment with a control group. I tried to calculate the cohen'...
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26 views

Meta-analysis: Calculating variance/ standard error of a mean difference for a within-subject design

I'm currently doing a random-effects meta-analysis. The studies that I'm analyzing come from a within-subject design where the same participants complete both the experimental and the control ...
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40 views

Linear regression from two meta-analysis outcomes in R metafor

First of all, I am sorry if this question sounds very basic, but I am new in meta-analysis and statistics and I don’t know how to execute what I have in mind. I have a dataset of 60 experiments with ...
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1answer
43 views

Meta Analysis with continues outcome - appropriate effect calculation

I am conducting a meta analysis with studies on psychological treatments with continues outcome variables. The included studies use two different scales (either 0-20 or 0-100) for each study i have ...
3
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1answer
90 views

Funnel plots and publication bias: Does asymmetry means a bad meta-model?

I have done a multi-level meta analysis with R, using metafor package. My questions relates to funnel plot asymmetry. (1) If a regression test suggested funnel asymmetry (i.e. suggested a ...
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31 views

Which meta-analytic method should I apply to my data set?

My dataset I have a dataset where Effect sizes are nested in Testing occasions, which are nested in ...
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0answers
30 views

Is it possible to estimate the posterior distribution of the difference of two means using published t statistics?

I am interested in using summary statistics from published papers to obtain posterior distributions for the difference of two means. In the setting of the classic t-test, we can imagine measurements ...
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0answers
18 views

Converting HR to OR for meta-analysis (or vice versa)

I've looked both in SO and others (Borenshtein's) and have yet to find an answer. I have some studies that provide an adjusted OR estimate, some HR, and then some with adjusted RR. I can subgroup and ...
3
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1answer
35 views

Why no talk of n-level meta analyses instead of three-level meta-analyses?

I have a data set that I'm going to use for a meta-analysis that has a lot of dependencies between the effect sizes. Because of this, I've started to look into how people normally handle this, ...
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23 views

Do i need to calculate sampling variance for meta-regression analysis?

My question concerns the calculation of sampling variance for studies using meta-regression or systematic review methods. I am using raw mean differences from different surveys conducted in the same ...
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1answer
43 views

Subgroups Cochran's Q test

I'm actually doing a meta-analysis to investigate the effect of an instructional method on learners' performance. I have calculated coehen's d and Hedges' g, the average global size, W (weight) for ...
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1answer
68 views

Funnel plots: random effect model versus mixed-effect model

I am using multi-level meta-analysis model in metafor package in R. The funnel plot for a random effect model (with moderator) and a mixed effect model (without a moderator) are shown below. Including ...
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2answers
51 views

standardized mean difference vs raw mean difference

Is there a difference between standardized mean difference and raw mean difference when conducting meta analysis or systematic review and the measurement scales are same, would SMD and raw mean ...
3
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3answers
155 views

Are multi-level models equivalent to saying multi-variate models?

Sorry if this sounds as a dump question but I was wondering: whether we can call the two-level mixed effect model that uses rma.mv in the ...
5
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1answer
48 views

Testing for publication bias in meta-analysis when effect is raw mean

I am conducting a multi-level meta-analysis using rma.mv in the metafor package in R. The effect size measure I am working with is the raw mean (...
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0answers
35 views

Using predict.rma with categorical and continuous moderators

I am trying to use predict.rmawith one categorical SNACK and one continuous CALORIES ...
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0answers
21 views

Predicting a parameter using the estimates of a series of studies, using study location and year as random effects

I would like to ask whether my analysis design is correct. I gathered all the trials on a series of drugs for a certain condition (second line therapy for advanced/metastatic lung cancer), published ...
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71 views

Effect of ignoring correlation between studies providing data for multiple comparison on the meta-estimate

I am addressing reviewer comments on a meta-analysis paper I performed on mean gastric pH in fed and fasted states. Some literature studies included in the meta-analysis provided data for multiple ...
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1answer
84 views

Meta-analysis of standard deviation using the `metafor` package in R: can we distinguish between the different types of variability?

I am doing meta-analysis of standard deviations of parameter X (gastric pH). My collated studies are conducted on humans and each study report mean plus/minus SD of gastric pH in the studied ...
2
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1answer
40 views

Fisher's combined test vs testing uniform distribution of p-values

In testing a global null hypothesis, with independent tests, the p-values are distributed as $U(0,1)$. There are many goodness-of-fit tests to check that the distribution is uniform. For example, this ...
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24 views

Can I obtain a mean difference from fold change data, number of participants and p values?

I have gene expression in fold change for cases vs controls. Therefore, below I have 4 times the gene expression of gene x in the cases compared with the controls. I have the number of participants ...
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2answers
24 views

Can I obtain the means for two groups using their mean difference?

I have a study which provides the mean difference for two groups (alongside 95%CI, SE, n and p-value). I would like to extrapolate the raw means to use in Revman to perform a random-effect SMD meta-...
1
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1answer
34 views

meta-analysis mixed model - polygons based on meta-regression

When using meta-regression with factor moderators, result differ a bit from using seperate estimation based on subgroup, even if the same model (mixed effects) is used for both. I understand the ...
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2answers
62 views

How to transform standard deviations from standard deviations

so I am doing a meta-analysis & have access to height and weight data (with SDs) and am trying to transform this into BMI. This is rather straight forward for the means, but I am not sure how to ...
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1answer
26 views

Heterogeneity evaluation in meta-analysis

I ran meta-analysis to combine findings of 15 studies. I used Comprehensive meta analysis software to generate the results. The purpose of the analysis is to see if the results are consistent and can ...
3
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1answer
49 views

Approach to conduct meta-analysis including data from structural equation modeling

I'm planning to write a meta-analysis on a topic in which there are both clinical trials and structural equation modeling papers. For clinical trials i can compute easily the effect size and analyze ...
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1answer
43 views

How to work out 95% confidence interval from odds ratio and standard error

$lnOR = -0.909 - (-1.707) = 0.798$ and its standard error is $SE(lnOR) = \sqrt{0.2182 + 0.3182} = 0.386$. The results of the adjusted indirect comparison suggest that x was less effective than y for (...
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1answer
45 views

How to calculate pre and post treatment Hedge's g effect size to use in meta-analysis of studies with no control group?

How to calculate pre and post treatment Hedge's g effect size to use in a meta-analysis for studies with no control group? Can you do it with just pre and post treatment means and standard deviations ...
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1answer
22 views

Calculation for the estimated sampling variance of individual group raw mean

I am conducting a meta-analysis where the effect size is the individual group raw mean (i.e., not raw mean difference). A couple of questions: How (in R: metafor or otherwise) is the estimated ...
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1answer
37 views

Interpreting meta-analysis risk ratios for dose-dependent effect

I have worked out the risk ratio of different doses of a drug relative to a placebo and want to find out if there is a dose-dependent increase in an outcome/effect I am looking at. I have the (for ...
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1answer
75 views

Using effect size estimates and p-values to determine effect size variance and standard error

I am in the process of conducting a meta-analysis. I am having difficulty replicating effect sizes that are in previous meta-analyses on the same topic. That is, for a given study I am not getting the ...
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2answers
48 views

Odds ratio meta analysis with no control group

Is it possible to conduct a meta-analysis odds ratio with just an experimental group (no control)? I am looking at several studies that have an experimental group, with a response rate equal to the ...