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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9
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1answer
13k views

How to calculate Standard Error of Odds Ratios?

I have two datasets from genome-wide association studies. The only information available is the odds ratio and the p-value for the first data set. For the second data set I have the Odds Ratio, p-...
11
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2answers
1k views

Why not perform meta-analysis on partially simulated data?

Background: A typical meta-analysis in psychology might seek to model the correlation between two variables X and Y. The analysis would typically involve obtaining a set of relevant correlations ...
10
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1answer
1k views

Alternative funnel plot, without using standard error (SE)

Before submission of my meta-analysis I want to make a funnel plot to test for heterogeneity and publication bias. I have the pooled effect size and the effect sizes from each study, that take values ...
9
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1answer
2k views

Metafor package: bias and sensitivity diagnostics

I am conducting a multi-level meta-analysis that includes some articles with multiple outcomes. Therefore I am using the rma.mv() function. Example code: ...
9
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1answer
1k views

What is the difference between a Frequentist approach with meta-analysis and a Bayesian approach?

Say I am performing an analysis looking at a particular health measure. I am interested in the difference in that measure between patients and controls and whether or not the difference is different ...
9
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4answers
11k views

How to calculate confidence intervals for pooled odd ratios in meta-analysis?

I have two datasets from genome-wide association studies. The only information available are the odd ratios and their confidence intervals (95%) for each genotyped SNP. My want to generate a forest ...
4
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1answer
203 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, ...
4
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2answers
5k 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?
4
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1answer
365 views

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 ...
4
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1answer
620 views

Method of meta-analysis of studies to determine mean blood level

Generally meta-analysis is done to determine the efficacy of some treatment as compared to controls. Is it possible to do a meta-analysis of different studies for mean blood level of a chemical, its ...
4
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1answer
305 views

Given sample size, group means, and misc. post-hoc range statistics, can you suggest a good way to estimate variance through simulation?

I previously asked this question about the validity of my solutions for for $SE$ given $n$, $\bar{X_i}$ and summary statistics from post-hoc multiple comparisons such as Fisher's $LSD$ and Tukey's $...
3
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1answer
430 views

Three-Level Multilevel Meta-analysis: What exactly are the three levels? Multilevel vs. Multilevel SEM Approaches

Completely edited: If a meta-analysis include many studies that reported multiple effect sizes within each study, multi-level meta-analysis is one way to account for this dependency in effect sizes. ...
2
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1answer
126 views

Meta-analysis data from studies comparing the “ecological” effect of a policy when some communities are shared by different studies?

I already made this question before (Is it appropriate to perform a meta-analysis of comparisons involving several communities where one of the communities was part of multiple studies?). I am making ...
1
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1answer
663 views

Interpreting a mixed-effects meta-analysis using the metafor package in R

This relates to an earlier question. Mixed effects meta-analysis using metafor package in R It is very easy to perform a mixed-effects meta-analysis e.g. using ...
9
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2answers
2k views

In a meta-analysis, how should one handle non-significant studies containing no raw data?

Let's say that I'm conducting a meta-analysis, looking at the performance of group A and group B with respect to a certain construct. Now, some of the studies that I'll come across will report that no ...
8
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1answer
19k views

Calculating I-squared (in meta-analysis, given tau-squared)

I have results of meta-analysis, which have been carried out and reported. These analyses report tau-squared as a measure of heterogeneity (and the other details from the analysis). I've been asked to ...
7
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1answer
316 views

Whether to apply structural equation modelling separately to each of a set of heterogeneous correlation matrices in a meta-analysis context?

I'm in the process of performing an Structural Equation Modelling (SEM) meta-analysis on some psychological data. Ultimately I want to examine a mediational model based on a set of correlation ...
7
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2answers
522 views

Practical data collection tips for performing a network meta analysis (mixed treatment comparisons)

As described previously in this post, I am currently working through issues with conducting a network meta analysis (also known as mixed treatment comparisons). For those unfamiliar with this method, ...
5
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1answer
408 views

Independent replication experiments yielding contrasting results; how to combine them?

Imagine a simple experiment, trying to answer a simple question. For example, is body temperature the same in men and in women ? To answer this question, let's say you sample 10 men, and 10 women, ...
5
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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 ...
5
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1answer
583 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 ...
4
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2answers
553 views

How can I compute a log odds ratio for a within-subject design that could be meta-analyzed with log odds ratios from between-subject designs?

Background and Problem I have a question concerning a meta-analysis combining effects from between- and within-subject designs using log-odds ratios (OR) as the metric of interest. I am familiar with ...
4
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1answer
1k views

Metafor rma.mv function: missing estimates for two levels of a categorical moderator

I am conducting a meta-analysis with several categorical moderators and one continuous moderator; I am also interested in an interaction between two of the moderators (outcome and scale). I have ...
4
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1answer
566 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 ...
4
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1answer
189 views

Principled ways of constraining $E[Y]=0$ when one of your regressors $\rightarrow$ 0

Consider the following ridiculous example. There is a real, non-ridiculous research question here, I promise -- I'm just a little bit uncomfortable posting what I'm working on on the internet in ...
4
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1answer
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 ...
4
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1answer
2k 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 ...
3
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1answer
2k views

Odds ratio and confidence interval in meta-analysis

I need to calculate the pooled odds ratio and associated 95% confidence interval for meta-analysis of 2 studies about the risk of bleeding. The only information I have is the odds ratios and 95% ...
3
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2answers
2k views

How does one run a meta-analysis on indirect / mediated effects?

I have two different datasets, and am reporting the same mediation analysis in both. The mediation in one study is clear, in the other less so. I am trying to run a small meta-analysis across both ...
3
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0answers
326 views

Is it possible to calculate a log-odds ratio with repeated trials?

Background and Problem This is a continuation of a question posted earlier (here) in which I describe a meta-analysis combining between- and within-subject designs using log-odds ratios (OR) as the ...
3
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1answer
265 views

Methods reference for meta-analysis of observational prevalence studies

I would like to conduct a meta-analysis, and later a meta-regression, of estimated prevalence rates in 40 observational studies. I'd like to know: a) what the true prevalence rate is likely to be b) ...
3
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3answers
393 views

Bayesian meta analysis of residual standard deviation using BUGS

I have a small number of studies where the same model was calculated and want to infer the typical standard residual deviation. I have the degrees of freedom, the sum of the squares SSR and the mean ...
2
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1answer
557 views

Converting an odds ratio to a standardised mean difference, so that it can be used in a meta-analysis

Where has the author got the blue 3 from, in line 2 of the code shown?
2
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1answer
7k views

How to do meta-regression analysis with SPSS?

I have done a meta analysis and heterogeneity is too high. I am working with (even/Total) for experimental and control groups to calculate the Odds Ratio. I have done fixed-effect and random-effect ...
2
votes
1answer
385 views

Mixed effects meta-analysis using metafor package in R

I would like to meta-analyse raw mean differences (MDs) in systolic blood pressures (BPs) according to soda intake (i.e. drinkers vs. non-drinkers). The problem is that there are important differences ...
2
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1answer
673 views

Test for homogeneity in meta-analysis with a large number of studies

So I am conducting some literature searches on behalf of someone. I stumbled across a meta-analysis which used 23 studies. It tested the homogeneity of the studies used, using what I think is a ...
2
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2answers
389 views

Variance Inflation Factor for Meta-Analyses

I've conducted a Meta-Regression Analysis for my Masters Thesis. However, my supervisor told me that I should check if the proposed moderating variables highly correlate. So I thought, that I can ...
1
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0answers
405 views

Multivariate meta-analysis in R: how to investigate network of variables [closed]

I would like to conduct a meta-analysis to investigate the interaction of three variables:hair color (dark/light), gender (male/female) and size (continuous). I have three studies reporting effect ...
0
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0answers
52 views

Standard error for difference between two independent gains

I've calculated an effect size for the difference between two standardized pre-post differences of two independent groups of subjects. That is: $[Mean_{dif_{group~1}}/SD_{dif_{group~1}}]-[Mean_{dif_{...
0
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1answer
1k views

What makes the results differ for fixed-effects models vis-à-vis random effects models in meta-analysis?

What makes the results differ for fixed-effects models vis-à-vis random effects models? The Cochrane Collaboration's website indicated that two models can produce different results for a meta analysis....
9
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2answers
580 views

Alternate weighting schemes for random effects meta-analysis: missing standard deviations

I am working on a random effects meta-analysis covering a number of studies which do not report standard deviations; all studies do report sample size. I do not believe it is possible to approximate ...
8
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3answers
3k views

Calculating effect sizes and standard errors for the difference between two standardized mean differences

I have two related questions, both of which are related to a meta-analysis I am performing where where the primary outcomes are expressed in terms of the standardized mean difference. My studies have ...
8
votes
3answers
7k views

Convert hazards ratio to odds ratio

In meta-analysis: How do we convert hazard ratios in some studies to odds ratio? There are case control and cohort studies to be included and some of them report hazard ratios. The raw data is not ...
6
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1answer
524 views

Estimate an overall correlation from the correlations within subgroups

Assume that you are working with variables $x$ and $y$ divided into groups two groups, $g_1$ and $g_2$. You know the following information: The number of people within groups $g_1$ and $g_2$, ...
5
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2answers
977 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 ...
5
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1answer
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 \\...
4
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1answer
104 views

Use of nested random terms in meta-analysis with a moderator

I am conducting a meta-analysis and I am struggling with the random structure when there is a continuous moderator and a nested random term. Starting with a simple example: ...
4
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1answer
7k views

How to combine two hazard ratios from the study for a meta-analysis?

I've been searching for a way to combine two hazard ratios from the same study for a meta-analysis, but found nothing. Does anyone know how to do this? Any thoughts would be great. Good Day, Simon
4
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1answer
594 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). ...
4
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1answer
652 views

How to combine data several studies with events?

I have a compilation of following data on 10 studies, all of which had 2 groups: a control group which received usual treatment and an active group which received an intervention. The subjects were ...