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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Post hoc analysis after meta regression

I am running a meta-analysis using metafor R package. I am comparing studies on a continuous variable, that can be synthetized by the mean. Such studies can be grouped in three blocks. I used a meta ...
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1k views

User weights in metafor

While reading "Conducting Meta-Analyses in R with the metafor Package" (http://www.jstatsoft.org/v36/i03/paper), I am wondering how model fitting works with user defined weights. In chapter 2.4 is ...
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Meta-analysis of RR and OR calculated from 2x2 tables in R using metafor

Background My question concerns the calculation of risk ratios and odds ratios for meta-analysis using the metafor package. I know it looks long, but please bear ...
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694 views

Simulation of random-effects meta-analysis yields biased tau^2

I need to realistically simulate study effect sizes and within-study variances for a random-effects meta-analysis in which the outcome is a relative risk. My question: why does this simulation lead to ...
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1answer
4k views

Calculating effect size (lnR) variances for studies with different study designs for use in meta-analysis

My question concerns the calculation of effect size variance for studies that are going to be included in a meta-analysis. I want to calculate variance so that I can weight each study by the inverse ...
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82 views

What would be the best statistical method to ascertain whether there is a significant relationship between X and Y?

I am doing a meta-analysis to find out if those with disease X also have disease y. I am trying to find if there is a significant relationship between these 2 diseases. However, I am only given the ...
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1answer
103 views

When calculating a meta-analytic prediction interval is it appropriate to report the back-transformed mean of that distribution?

The Problem I have been working on an epidemiological meta-analysis of prevalence values, measured as proportions but analyzed in logit-space. The conditions I study are quite rare (<5%) so all ...
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344 views

Looking for beginner resources with effect sizes

First post here; first I would like to say that I have no background in stats whatsoever and not so much in math either (enriched high school math, and that's it). I started an MA and we have to do a ...
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2k views

How to calculate weighted Hedges' g effect size in meta-analysis when some effect sizes share a control group?

I am trying to do a meta-analysis using Hedges' G as the effect size. Questions Some of the studies have different groups but the same control group. How does this change the computation and ...
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2answers
1k views

Statistics for multi-test replicated correlation analysis

I'm analyzing pairwise correlations of time series between two different types of microarrays done for several samples as biological replicates. So, I have M1 number of variables on type 1 array, M2 ...
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2k views

Classical measurement error model in R

I'm not sure if this is precisely a measurement error model or not. I'm working on performing meta analysis, and the model I'm starting with is fairly basic. \begin{aligned} X_i &= \mu_i + e_i \\...
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2answers
179 views

Estimating population correlation based on current data and a previous study

Assume: A previous study looking at the relationship between $X$ and $Y$ obtained a correlation of $r = 0.50$ using a sample of $n = 100$. The raw data is not available. The current study also ...
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37 views

Strange result (v small CIs) using Hartung-Knapp Correction in meta-analysis

I've come across a strange result using a Hartung-Knapp correction (in the metafor::rma() function), when I have a small number of studies, and very similar effect sizes. What I typically expect is ...
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1k views

Which is the best method for meta-analysis of diagnostic test accuracy studies?

I am conducting a meta-analysis of diagnostic test accuracy studies focusing on myocardial perfusion imaging. I have used first Meta-Disc, but only for descriptive purposes, as it is clear that ...
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4k 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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4k views

How to combine data from 5 surveys from the same population spanning 10 years

I have results from 5 surveys each 2 years apart and let us assume that no subjects are selected in more than one survey. The sampling method used in these surveys are biased and I have sampling ...
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1answer
2k views

How to combine many Goodman-Kruskal gamma measures?

I have 5 samples (from the same population). I want to calculate the Goodman-Kruskal gamma ($\gamma$) for the population, based on the gamma of the 5 samples ($G_i$). Each data has 2 ordinal ...
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666 views

How to compare the variability of two measures from meta analysis?

I have two measures from each of 20 studies. Random-effects meta analysis has been performed for each of the two measures, and for each measure I have two values to indicate data variability, cross-...
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288 views

Pooling homogenous studies vs. using meta-analysis/bayesian

I am working with a student who has collected about 300 participants for his thesis. After collecting 100 participants, he analyzed the data. I had just recently read of a "mini-meta-analysis" ...
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720 views

Interaction effect of 2x2 ANOVA in meta-analysis

I want to meta-analyze the interaction effect of a 2x2 ANOVA. (I am not talking about an interaction in the meta-regression, as in this question but about an interaction as the focal effect that ...
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2k views

What is the equation for combining standardized mean differences across multiple studies?

I am trying to come up with a combined/pooled standardized mean difference for meta-analysis of a dozen or so studies that have the same binary predictive groups and the same continuous outcome ...
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1answer
143 views

Meta-analysis of 3 regions' data for 5 years

Can we do a meta-analysis of data of 3 regions. A particular disease was treated with the same treatment but implemented thoroughly in 2 regions and not so thoroughly in 1 region. How to proceed with ...
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Meta-analysis with mean and sample size but without standard deviation?

I'm doing meta-analysis for a treatment done in seeds. I have approximately 130 series with value of the control mean (Xc), its treated homologous mean (Xe) for crop yield and the number of ...
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589 views

Multilevel meta-analysis with non-independent effect sizes: correct model?

I'm conducting a meta-analysis on standardised mean difference scores. Some studies provide multiple effect sizes, thereby violating the assumption of independence. An example is given below (all ...
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643 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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What is the difference between fixed effects model and random effects model for a meta-analysis of sample correlations? [duplicate]

Fixed effects model seems to differ from random effects model for a meta-analysis of sample correlations in terms of assumptions. What is key assumption for a fixed effect model?
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184 views

Calculate the standard deviation from a hazard ratio's confidence interval

I often come across hazard ratios and their confidence intervals in the published literature on clinical trials. I would like to calculate the standard deviation from these confidence intervals for ...
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567 views

publication bias in meta-analysis of diagnostic tests

How can investigate publication bias for diagnostic tests in meta-analysis with R? I saw this topic "Publication bias in meta-analysis of diagnostic accuracy in R?" but there is no answer yet!
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Combining multiple outcomes in studies (no meta-analysis)

I'm looking for a way to combine effect sizes (mean difference) and variances for several single studies but I don't want to conduct an overall meta-analysis. That means I'm only looking for an ...
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R-Metafor: Meta-analysis and mixed effect model

This is an example of my dataset ...
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2k views

nonlinear meta-regression

Can someone point me to a basic explanation of theory and methods for fitting nonlinear curves (particularly quadratic functions) to meta-analytic data? I have a set of effect sizes that are clearly ...
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3k views

Mixed-effects meta-regression with nested random effects in metafor vs mixed model in lme

I have a collection of continuous data from the literature, including the mean, the standard deviation and the number of observations for both experimental and control groups, as well some ...
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4answers
2k views

Using mvmeta to perform a network meta-analysis

A few months ago, I posted these two questions about practical considerations in collecting data for a network meta-analysis and the available R packages that can analyze such data. For those ...
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945 views

Is this the correct way to calculate $MSE$ from $SS_{\text{treatment(s)}}$, $df_{\text{treatment(s)}}$, $F$?

As described in a few of my previous questions (here and there), I am interested in deriving summary statistics from statistics reported in the literature. I would very much appreciate any advice ...
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112 views

Robust Variance Estimation in Bayesian Meta-analysis

BACKGROUND I am conducting a meta-analysis using the brms in R with structure akin to the following (leaving out priors, etc. ...
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649 views

Is it possible to meta-analyze means on different scales?

I have study-level means/SDs reflecting depression symptom severity from multiple single-group studies. I do not have access to participant-level data. The studies all use different measures, and I ...
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1answer
871 views

Combine crude events and Hazard Ratio in Meta-analysis

I'm running a meta-analysis on several studies; most of them have crude event numbers that I can put in my software, but other ones have hazard ratios with 95% C.I. reported and no crude number ...
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430 views

metafor package and bootstrapping

I have issue combining metafor and boot package. My original meta-analysis model is following and this runs well: ...
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1answer
1k views

Metafor package in R: Ranktest for multivariate meta analysis

I have done a multivariate meta analysis with R, with support from metafor package. I am using rma.mv-method which gives an R object of class c("rma.mv","rma"). My question is about looking for funnel ...
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1answer
240 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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829 views

Psychometric Meta-Analysis in R

I would like to perform a psychometric meta-analysis of stigma measurement instruments. A potential candidate for a specific analytical approach could be in my opinion the Hunter and Schmidt method: ...
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1answer
836 views

Two Study Meta-Analysis: Fixed- vs. Random-effects and heterogeneity

I browsed through several papers and discussion but I am still not sure what is correct. I conducted two studies on the same topic using similar methods and the same design (independent t-tests). ...
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1answer
389 views

Publication bias and proportional data in metafor

I have been recommended to use rma.glmm for an analysis of proportions and I am in need of publication bias tests. Are any possible in metafor given proportional data, please? The analysis is using ...
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2answers
5k views

How to perform a meta-analysis of regression coefficients?

I want to perform a meta-analysis but the included studies use different models to analyze the data. There are Pearson correlation (3 studies), Spearman correlation (1 study) and several studies (~7-...
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1answer
390 views

Combine 2 groups based on the regression coefficient

I have two groups of people, N=211 in group 1, N= 310 in group 2. I would like to combine these groups because they share a certain characteristic that I am interested in. The groups are used in a ...
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1answer
2k views

How to convert the standard error of the log odds ratio to the odds ratio standard error

I am using the log odds ratio (and its standard error) for meta-analysis. I want to convert back to odds ratio to write up the results... maybe i'm putting in the wrong search terms but can't find ...
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1answer
239 views

Most appropriate way to construct overlapping dummies

What would be the most appropriate way to construct dummies with theoretical overlap? I'm doing a meta-regression of studies looking at the effect of certain interventions on X. Some studies use ...
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1answer
1k views

Meta-analysis: is there a way of including dependent effect sizes without averaging across them

I'm running a meta-analysis with a binary outcome (succeed/fail). I am primarily interested on the effect of predictors related to the study (e.g. age of participants, type of task) on the binary ...
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3answers
890 views

Data imputation for meta analysis using mice package in R

I have a data-set with 32 effect size estimates- only 11 of which report a value for the continuous moderator of interest (the samples anxiety level). A complete case analysis (restricted to the 11 ...
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190 views

Is it standard practice to omit studies lacking an estimate of sample standard deviation from meta-analysis?

It appears common among meta-analyses to omit studies that do not provide an estimate of sample standard deviation. For example, a previous question reviews some ways to estimate $\sigma$ from ...

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