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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15 views

Should I be running a meta-analysis?

I am working on a project that assesses the slope of the species area curve across multiple studies (right now I have 35 studies). I have slope values for all these studies and all of these slopes ...
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Transforming mean-absolutes to mean differences for meta-analysis

For a meta-analysis project, I have been tasked to submit data in Reviewmanager software. However, often I come across papers that report on average pain or ...
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Can correlations between all variables be extracted from PCA/RDA biplots?

I am performing a systematic review of the literature for my dissertation, and I need to extract the relationship between two variables from the results of multivariate analyses, particularly ...
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How do you calculate standard deviation for a mean change, given mean 1, SD 1, mean 2, SD 2, and total n?

How do you calculate standard deviation for a mean change, given mean 1, SD 1, mean 2, SD 2, and total n? For example: n=590. Initial mean is 26 with a standard deviation of 8. The mean at the end ...
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Converting standardised effect size (d / SMD) to r

I am looking at conducting a meta-analysis the relationship between BMI and a personality characteristic. I want to conduct the meta-analysis on correlation coefficients, and many papers report the ...
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Meta-analysis of proportions in Stata 16

I have recently upgraded by Stata to version 16, specifically because of the new Meta-analysis functionality. I have previously conducted a meta-analysis of study proportions using the 'metaprop" ...
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Difference in proportion across study types based on count data from multiple studies?

We have the following situation. We have collected count data from a number of studies. Specifically, we looked at the number of people of each race in each study's cohort. We also collected a number ...
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difference in effect strength / effect significance depending on number of included effects in mixed model

I am very new to mixed random effect models and am struggeling with the interpretation of the output: I set up a model with 1 random effect and 3 fixed effects (I will name these A, B and C). The ...
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What is the best way to do a metanalysis for half-life?

I am working on a meta-analysis on pesticide degradation, where the quantity of interest is the difference in half-life in different environments. However I am in doubt of how to use the data; in all ...
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1answer
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Random Effects Meta Analysis without Standard error

I am trying to code up a random effects meta analysis in R. I was given some data and I noticed none of the data comes with Standard error. The only thing provided are the Risk ratios, Confidence ...
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25 views

Meta-analysis using mixed-effects model with moderators where response variable is effect size - is it appropriate to remove the y-intercept?

Greetings fellow statisticians, We're working on a meta-analysis looking at the effect of mindfulness based interventions [MBI] on self-compassion. We've computed Hedges' ...
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Best meta-analytic approach with Mean, SD, Sample size for regional values of MRI measure

I'm interested in evaluting the evidence in the literature I've collected for spatial/anatomical variation in an MRI measure. The data consists of mean values, standard deviations and sample sizes, ...
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Calculate/understand the total sample mean of a binary dependent variable from the fixed effect estimates of a model?

was hoping you could help me to understand the model that I have just fit; in particular, I'm interested in the calculus of how the fixed estimates fit back together to make estimates for total sample ...
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Fixed-effects (plural), fixed-effect (singular), random-effects models

In its Procedures Handbook 4.1 (January 2020) , the What Works Clearinghouse (WWC) announces calculating the weighted average of the effect sizes in its meta-analyzes using the fixed effects model (...
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Adding mean change values as data inputs on Revman for a meta-analysis

I am currently conducting a meta-analysis using Cochrane's Revman software. Very briefly, I am interested to find out whether an eHealth intervention was effective in improving health outcomes (e.g., ...
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Do we need fixed effects in Neural Networks?

I have a background in econometrics, and generally when we are working with panel data (i.e. there's a time-series as well as a cross-sectional dimension), we would include fixed or random effects. ...
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Combining coefficients of two independent linear regression

I have two datasets. Dataset 1 has $P$ measurements of dependent variable $Y$ and independent variable $X_1,,,X_N$. Dataset 2 has $Q$ measurements of dependent variable $Z$ and $X_1,,,X_N$. $Y$ and $Z$...
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Log-transforming a mean - what to do with SD?

I am doing a meta-analysis of means. I have gathered means, SD and N from a set of studies. I do not have access to the raw data of the means. After doing an Anderson-Darling test, I found that the ...
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Fisher's method for combining p-values

I'm using the sumlog function in the metap package of R, and have a few questions about the nuts-and-bolts of this function: 1)Some of my p-values are reported as '<0.001'. How do I include these?...
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30 views

How to calculate pooled mean difference?

I'm currently doing a simple pooled analysis study; which, unlike meta-analysis, does not involve weighing between studies. However, my outcome of interest involves continuous outcome (pre-...
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How to interpret meta-regression results with significant moderators but no significant overall effect?

I'm conducting a meta-analysis where I have a given set of studies, each with multiple effects (correlations in my case) I'm interested in. Each correlation coefficient answers a different research ...
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1answer
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Meta-analyzing Likehood ratio or wald test outputs

Hope your day is going well! I've been reading a lot on the Wald test and likelihood ratio test recently because it is the output of my RNA sequencing data. I was interested in meta-analysis of ...
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Meta-analysis of standardized regression coefficient (beta coefficient)

I am trying to do a meta analysis on the effect of smoking with hypertension. Some of the studies used 'beta coefficient' and its confidence interval as the effect of smoke exposure with increase in ...
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Converting probit coefficients into effect sizes for meta-analysis

I am conducting a meta-analysis but the raw study coefficients are probit coefficients. I am planning to convert these to log odds to meta-analyse through the formula: 1.61 * probit_coefficient. Q1) ...
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Comparing effect sizes across multiple groups within meta analysis

I have multiple studies on a particular effect, each study tracks certain other criteria, and each has a control group. The units of measurement in each study are not always convertible between each ...
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Meta-analysis with incomplete data

I'm doing a meta-analysis comparing infection rates in 2 sub-types of liver operations (say Big surgery Vs Small surgery). I have a few studies which compare the 2 but other studies that only report ...
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1answer
58 views

Meta-analysis with only p-values

I am doing a systematic review on the risk factors that predict infection after liver and pancreatic surgery. These risk factors include parameters like age, sex, smoking, pre-operative chemo etc. I ...
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57 views

Choice of box size and weights for a forest plot from random effects meta-analysis

I am doing a random-effects meta-analysis where the variable is measured in standardized mean differences. The actual measures vary, but are related to drug use in rats and control vs. treatment. I ...
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Compute standardized mean difference and its standard error from regression-adjusted mean and 95% CI for 2 groups

I am working on a meta-analysis (using aggregated data), where the outcome is a continuous variable. One study reported post-treatment outcome values as regression-adjusted mean and 95% CI in each of ...
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Calculate correlation between different effect sizes retrieved from individual studies in meta-analysis

I am working on a meta-analysis where i have two different effect sizes for each study (2 variables A and B that are measured after a specific treatment). I can run two different meta-analysis on ...
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Generic inverse variance meta-analysis with metagen function, how to report results?

I have recently performed a pairwise meta-analysis where I pooled the effect estimates and variances of different studies that either reported mean differences and odds ratio for the two arms using ...
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1answer
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Combining effect sizes to learn about the difference between two groups?

I am interesting in learning if there is difference between the control and the treatment group in a paper I am reading. Unfortunately the paper only compares the respective conditions to a 0 effect ...
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1answer
30 views

Meta Analysis with Likelihood Ratios

I am currently writing a protocol for a systematic review and meta analysis to analyze the available evidence regarding epidemiologic studies on risk factors for pneumonia. The end goal of the ...
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How to find standard error or standard deviation of the percent difference between two prevalence values?

I am having trouble working out how to find the standard error or standard deviation for a column that contains the percentage points difference for two prevalence values. I have general practice ...
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1answer
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How does pooling affect variance?

Suppose you are looking at the prevalence of a certain disease and you can detect this disease in fecal samples. How does having a bunch of pooled fecal samples (i.e., taking a fecal sample from 5 ...
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48 views

Meta-Analysis without a Control Group

I am conducting a systematic review and meta-analysis which is investigating health-related quality of life in a particular patient population. I am having difficulties with conducting the meta-...
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Why is my meta analysis OR and 95% CI less precise than my study results? [closed]

I am trying to perform a simple weighted average meta analysis of 2 odds ratios from 2 studies (I will be adding more studies when I get the results). However, when I meta analyse using the METAFOR ...
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1answer
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Should we do a meta-analysis of non-inferiority trials?

Since non-inferiority trials are designed meticulously to achieve an effect size demonstrating no significant difference between treatments, so there may be certain essential differences in design of ...
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Transforming reported effects at sample means for a meta-analysis

I'm doing a meta-analysis about tax avoidance (like this: https://poseidon01.ssrn.com/delivery.php?ID=...
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How to Calculate Observed Variance in a Random-Effects Meta-Analysis

I've received a revise and resubmit on a meta-analysis investigating the effects of a positive psychology intervention on depression and anxiety symptoms. I used Hedges' g as the effect size with a ...
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1answer
23 views

Data fusion for multiple correlated t-tests

Question is similar to this unanswered question. I have several data sets each corresponding to a different location. Every row of each dataset contains a measurement of the same quantity taken at a ...
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How do I test whether the distribution of effect sizes are different across intervention types?

I've extracted 3,456 Cohen's d effect sizes from published studies, and categorized each based on intervention type (four different intervention types). I did this to understand the distribution of ...
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Possible NAs in Beslow estimation with repeated data?

I would like to seek your advice on a problem I encountered recently. I bootstrap on a test that includes a Breslow estimate for survival data. Since these are meta-analyzes, I am bootstrapping on ...
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How to bootstrap a statistic calculed in a meta-analyis?

I have calculated a statistic in a meta-analysis of individual data and I want to bootstrap it to obtain the variance (no analytic expression is available) to make a test. First, I was naively ...
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Meta-analysis with pre-weighted data

does anyone know of any references that speak about whether studies can be included in a meta-analysis if the study is already given some kind of weighting factor? For example, large scale survey ...
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What is the formula for combining Hedges' g across studies?

If I have Hedges g for a bunch of different studies, what is the formula for combining them? EDIT with more detail. This is part of a meta-analysis. Each study was small, with N usually equal 6 or 8 ...
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1answer
32 views

'rma.mv' function output- fisher Z or raw correlation

I would like to ask a question regarding the output of the rma.mv function. I had raw correlations which I transformed into Fisher's Z correlations using the 'escalc' function. Then, I performed a ...
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Is the shrinkage of subgroup analyses in meta-analysis an example of Stein's paradox?

This paper writes (edited for concision): Consider, a doctor in Germany confronted by a meta-analysis of long term‚ $\beta$ blockade after myocardial infarction. Although a robust beneficial effect ...
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Selecting the correct clustering variable when calculating robust meta-analytic tests and error terms for dependent data [closed]

Background I am revising a meta-analysis for publication and have been asked to adopt a multivariate modelling approach using the rma.mv and robust functions within the metafor package in R. ...
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Pseudoreplication in studies used in meta-analysis (problem with sample size)

We are conducting a meta-analysis, but we have problems with pseudoreplication within our primary studies. Most of the studies use correlation analysis (but we also have linear regression and GLMM) ...

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