Meta-analysis refers to methods focused on contrasting and combining results from different studies, in the hope of identifying patterns among study results, sources of disagreement among those results, or other interesting relationships that may come to light in the context of multiple studies.

learn more… | top users | synonyms

1
vote
0answers
33 views

Meta-analysis - Multiple Outcome measures for the same population

Basically, I am trying to include some binary data into a meta-analysis and not sure how to include this dataset. If you look at the attached table, each red square that i drew depicts an ...
2
votes
1answer
22 views

Hartung-Knapp CIs in meta-analysis with two trials

I'm having trouble convincing my collaborators that we should use the Hartung-Knapp correction when we have only two trials. This paper seems pretty convincing ...
2
votes
2answers
48 views

meta analysis of odds ratios

I would like to work on a meta analysis project, I have kept 8 studies that satisfy my criteria and I'd like to continue with these. Their results are formed as odds ratios (OR) and confidence ...
0
votes
0answers
25 views

Transformation of means and sd in meta-analysis

I am doing a meta-analysis based on the means and standard deviations collected from many other studies. The distribution of the data indicated that I need to transform the data. However, the authors ...
0
votes
0answers
10 views

Meta-analysis of skewed data with low event rate (single-arm studies)

I am trying to pool the data from several single-arm studies regarding the re-infection rate of a certain disease using STATA. From each study, I have obtained the no. of re-infections, and the ...
1
vote
1answer
91 views

Is it valid to use a generalized model with no replicates

I've got a designed experiment that is a long-term agricultural station. The field is divided into 11 rows and 6 columns (each column has two sub-columns). Each resulting plot represents a unique ...
1
vote
0answers
39 views

Meta-analysis: Difference between direct and indirect restriction of range

Looking at meta-analysis for personnel selection procedures, I am having really big troubles to figure out the difference between concepts of direct restriction of range (DRR) and indirect restriction ...
3
votes
1answer
44 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 ...
2
votes
1answer
95 views

R-Metafor: Meta-analysis and mixed effect model

This is an example of my dataset ...
0
votes
0answers
28 views

What are the quantitative methods alternative to Meta-Analysis?

What are the alternative statistical quantitative synthesis methods for combining studies, if we can't apply meta-analysis because of the heteronegeity or the shape of the data, for the data set of ...
0
votes
0answers
46 views

Which method should I use to combine the data of my studies?

I want to make a meta-analysis on household consumption expenditures elasticity data. In these studies that I've got; methods and regions and etc. varies according to studies. But at last, the results ...
1
vote
0answers
46 views

Meta analysis of multiple-treatment-multiple-endpoint studies

I have read some things about Meta Analyses for stochastically dependent effect size (e.g. Gleser and Olkin (2009) in The handbook of research synthesis and meta-analysis (2nd ed.). I understood ...
2
votes
0answers
21 views

Alternatives to Fisher's method?

I'm using the Mann-Whitney U test to compare scores from a foreground (n ranging between 5-500) to a large background (up to 2000). Since my foreground is quite small I've been taking smaller random ...
4
votes
1answer
32 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 $g_2$, ...
3
votes
1answer
42 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 ...
2
votes
1answer
34 views

Converting Adjusted Odds Ratios to its RR counterpart

I am doing a meta-analysis of studies which reported their estimates sometimes as OR and sometimes as RR. I wanted to convert the OR to RR, so that I can pool them together. I know that I can use this ...
2
votes
1answer
42 views

Calculating heterogeneity (Cochrane Q and I^2 statistics) in random effect model

I want to ask whether I can calculate the Cochrane Q statistics and I^2 statistics in random effect model. I collected some data from different areas and want to compare the prevalence of allergic ...
2
votes
0answers
42 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 ...
0
votes
0answers
40 views

Meta-analysis with a categorical explanatory variable

I am attempting to fit a model to my data for meta-analysis I'm working on. The data is structured as follows: ...
0
votes
0answers
25 views

Meta analysis on multiple endpoints and unknown covariance

I am doing meta-analysis on intervention studies on human subjects where a number of measures were obtained before and after the intervention in a treatment and a control group. We categorize the ...
3
votes
1answer
71 views

Is stratified meta-analysis more or less objective than meta-regression?

Reviewer asked me why I use meta-regression as a way how to deal with heterogeneity among effect sizes instead of conducting stratified meta-analysis. I tried to google "stratified meta-analysis" and ...
0
votes
0answers
32 views

Difference in proportion: Pre-post intervention-control study design

I am conducting a meta-analysis where I want to compare the proportion of samples pre- vs post- intervention. To do this, I have been calculating the difference in proportion (Post - Pre) as the ...
0
votes
0answers
98 views

Meta-analysis of percentages at baseline and follow-ups in R using metafor package

I would like to conduct a meta-analysis in the context where I have studies available that measure a continuos variable at multiple time points (0, 1, 2, 3, 4, 5). Time 0 represents the baseline where ...
0
votes
0answers
31 views

meta-analysis, effect sizes for standard deviations

Is there any possibility to calculate effect sizes for the differences of standard deviations of two groups? (Is there any possibility to calculate the difference in the standard deviation between two ...
1
vote
0answers
24 views

Mixing ITT and TOT/LATE Effect Sizes in Meta-Analysis

I have a question concerning the coding of Effect Sizes for a large (educational) Meta Analysis with mostly latent outcome variables. Some studies provide "Intent to Treat" Data from which I ...
1
vote
0answers
12 views

Multiple groups - how to regularise estimate of level 1 parameters based on level 2

I am fitting some relatively complex structural equation models, but the specific model is not so important. I am estimating multigroup models, such that one parameter is completely free across ...
1
vote
1answer
25 views

Meta-analysis with studies reporting both positive and negative estimates

I'm organizing a meta-analysis on performances with studies showing sometime positive and sometime negative estimates. Sometime the result of the study is in a positive direction, with higher scores ...
0
votes
1answer
38 views

How do I translate logistic regression output into logged OR (and SE) for meta-analysis?

I'm attempting to conduct a meta-analysis using (logged) odds ratios, I'm using the Generic Inverse variance method (Review Manager) as some of my studies only report odds ratios and CIs (not raw ...
2
votes
1answer
48 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 ...
3
votes
0answers
34 views

Meta-analyses for variance rather than means

What are the main complications / differences when conducting a meta-analyses where the metric of focus is not effect size (i.e., means) per se, but instead estimates of variances from models? Nods ...
1
vote
1answer
57 views

Calculating the correlation between difference scores from the correlations within timepoints

For a meta-analysis I am conducting, I need to know the correlation between two sets of difference scores. For example, imagine a study in which the researchers measure variables $x$ and $y$ at time ...
3
votes
1answer
183 views

independent replicate experiments yielding contrasting results

This is a simple experiment, for thinking efficiently about a real problem much more complicated... Imagine a simple experiment, trying to answer a simple question. For example, is body temperature ...
0
votes
0answers
20 views

Meta analysis, joint posterior distribution of study effect

Meta analysis (with common study variation $\sigma$) often assumes that: $$ X_{i,j} | \theta_i \overset{ind}{\sim} N(\theta_i,\sigma)\\ \theta_i \overset{i.i.d.}{\sim} N(\mu,\tau) $$ where ...
0
votes
0answers
23 views

When is appropriate to combine two treatment groups from one study into a composite whole for a meta-analysis?

The treatment groups I would like to combine appear to be virtually the same, at least by generic label for each group, e.g., groups with the same treatment but implemented at different sites or ...
0
votes
0answers
36 views

Meta-analysis: design mixed-effects model in R

this is an example of my dataset: ...
0
votes
1answer
55 views

Meta analysis: transform forest graph output to percentage effect in R {metafor}

I need the forest graph expressed as % effect. I have run the model with the log ratio, and I know I could back-transform using transf=exp, which would plot the forest graphs expressed as the ratio ...
1
vote
0answers
38 views

Can Hedges' d be used to compare unlike effects?

I've got a question related to the use of Hedges' d in a meta-analysis of insect fitness information. Here is a link (pdf) to the paper I'm working with. In the appendices, the fitness information ...
3
votes
1answer
76 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 ...
1
vote
2answers
54 views

Using variance from a Jeffreys prior in a Prevalence meta-analysis

I am doing a meta-analysis on a group of studies, where the observation is a rate (no. of successes / no of trials). Some of the studies have small sample sizes (n<10) and/or did not observe any ...
0
votes
0answers
34 views

comparing two sets of meta-analysis

I have two subgroups (high / low BMI) on which several measures where recorded and analyzed on by various papers in a treatment and a control group. I was trying to verify if, for each measure, the ...
1
vote
0answers
39 views

Meta-analysis: Talking about power and inference (to power)

I need a little help or reassurance concerning how to explain power "to power", i.e. to decision makers that are not well versed in statistics. The problem is this: I have done three empirical ...
1
vote
1answer
130 views

Mixed-model meta-regression

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 ...
1
vote
1answer
47 views

Metafor package: RMA and testing for interaction in two studies (Altman & Bland 2003)

I have traditionally used this simple test of interaction (http://www.bmj.com/content/326/7382/219) for comparing effect sizes between studies, and I would like to start performing it in R. Although I ...
2
votes
0answers
24 views

How big is the risk for regression in a single arm meta-analysis?

I'm performing a single arm meta-analysis of continous data deriving from efficacy evaluation of control gorups surgical procedure. How big is the risk for regression to the mean? And How it could ...
4
votes
0answers
103 views

How to deal with unequal sample sizes while fully embrace a dataset?

Imagine the situation: Mythical Seafolk use holes in the seabed as their burrows. Each hole has two parameters - diameter and depth. Majority of holes are unoccupied due to their surplus (n = 235). ...
0
votes
0answers
76 views

Effect sizes in within-subject design on R

I'm doing a meta-analysis but I need your precious help on couple things : 1) First, on R, in the compute.es package, I found only effect sizes computation formula ...
6
votes
1answer
142 views

Oddly large R squared values in meta regression (metafor)

I am using the metafor package in R. I have fit a random effects model with a continuous predictor as follows SIZE=rma(yi=Ds,sei=SE,data=VPPOOLed,mods=~SIZE) ...
2
votes
1answer
126 views

Difference between Meta-Analysis, Meta-Regression and Moderator-Analysis

What is the difference between the classic meta-analysis (that aggregates effect sizes from a sample of studies to a summary effect size), meta-regression analysis and moderator analysis? As I ...
2
votes
0answers
46 views

Independence of effects in meta-analysis and meta-regression

In meta-analysis, I know that an important assumption is independence. Clearly, if we want to estimate a pooled effect size, its best if each effect comes from an independent sample of observers. ...
0
votes
0answers
24 views

APA-style forest plot using metafor [duplicate]

I have produced a forest plot visualizing results of a meta-analysis, trying to meet the requirements according to the APA style, i.e., statistical terms to be italic, e.g., k = 10, or sub-scripted, ...