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 ...
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 ...
2k views

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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
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 \\...
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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
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-...
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" ...
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 ...
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 ...
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 ...
2k views

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 ...
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 ...
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 ...
6k views

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?
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 ...
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!
1k views

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 ...
1k views

R-Metafor: Meta-analysis and mixed effect model

This is an example of my dataset ...
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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 ...
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 ...
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 ...
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 ...
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. ...
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 ...
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 ...
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: ...
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 ...
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 ...
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: ...
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). ...
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 ...
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-...
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 ...
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 ...
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 ...
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 ...
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 ...