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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7 views

Can three-level meta analysis be random-effects model and/or fixed effects model?

I am learning three-level meta-analysis and trying to deeply understand how this new relatively new approach fits into the more commonly used general meta-analysis (...
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21 views

Pooled analysis of studies with only intervention arm

I want to perform a pooled analysis of studies including only a treatment arm, so no proper control groups are available. Studies present data about subjects before the treatment and after treatment, ...
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1answer
26 views

How to convert beta from logistic regression into cohen's d?

Is there a way to transform a coefficient from a logistic regression into a cohen's d value? I am trying to calculate the cohen's d for a study with a binary DV while controlling for another ...
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26 views

How to convert sampling sampling variances for a meta-analysis using raw means as effect sizes?

I am conducting a meta-analysis using raw mean scores as effect sizes (i.e., reported test scores on a certain standardized test). I found a calculation formula for sampling variances provided by, e....
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43 views

Meta-analyses using raw mean as Effect Size, instead of mean differences (e.g., Cohen's d)

I am writing up my meta-analysis using raw mean scores as effect sizes (i.e., reported mean scores on a certain standardized test) using the metafor package in R. ...
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16 views

Trelllis plots in meta-analsysis [closed]

I am trying to plot, a trellis plot. But I get an error and I don't know what its means. ...
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20 views

Multilevel regression meta-analysis : no existing package? (Edited)

The question is in the title. Meta-analysis with binomial distribution I'm trying to do a meta-analysis on occurence of an event across different studies. For each study $i$ ($i=1,\dots,N$), I have ...
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8 views

How do I use clinical trials as random effects in a cox regression model stratified according to trial for an individual patient data meta-analysis? [closed]

I am performing an individual patient data meta-analysis and pooling several trials. I have the data all combined in a single data set and want to fit it in a Cox regression model stratified according ...
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1answer
19 views

Prediction Intervals by meta package

I am using meta 4.9-5 package for conducting meta-analysis on correlation data. But I cannot figure out why it is unable to calculate lower and upper prediction intervals even I have set prediction = ...
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1answer
47 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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35 views

Predicting disease based on eeg electrode power features and source power estimates

The dataset consists of Eeg electrode power features in all power bands(alpha, beta, delta..both relative and absolute) and source power features (obtained after source estimation) in addition to ...
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17 views

Why is Metafor R package giving an I2 for fixed effects meta-analysis model (rma.uni)? [closed]

I'm trying to run a fixed effects meta-analysis using the Metafor R package and in the documentation I read that it does not return an I^2 for fixed effects models, only for random effects models. ...
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2answers
125 views

Are there good alternatives to Cochran's Q test for heterogeneity in meta-analysis?

We used the Q test to determine heterogeneity with p-values <0.10. A highly recognised statistician commented that the Q test has low power and that it should not be used to determine presence of ...
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1answer
28 views

Regression multi-level meta-analysis with binomial data in R: no existing package? [closed]

The question is in the title. Meta-analysis with binomial distribution I'm trying to do a meta-analysis on occurence of an event across different studies. For each study $i$ ($i=1,\dots,N$), I have ...
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1answer
42 views

What's the statistical method of comparing the amount of pre-post difference scores of between groups?

I am currentnly doing a meta-analysis of the effects of social cognitive training on social cognitive function of patients of schizophrenia. There are wo conditions: treatment group receving social ...
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1answer
50 views

model test p-value>0.05 but intrcpt <0.05 [closed]

Mixed-Effects Model (k = 21; tau^2 estimator: SJ) tau^2 (estimated amount of residual heterogeneity): 0.2301 (SE = 0.0752) tau (square root of estimated tau^2 value): 0.4797 I^2 (...
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19 views

Assembling meta-analysis data with paired data for metafor

I am trying to assemble a meta-analytic dataset for computing yi and vi for metafor. For this dataset, I am including paired data (i.e., one sample of participants that completed upright and inverted ...
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2answers
80 views
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1answer
179 views

Variance–covariance matrix in meta-analysis of variation metafor

I'm conducting a meta-analysis on estimating a gold standard measure from other simpler measures. To determine the error of estimation, I derived the standard deviations of the differences between the ...
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1answer
82 views

What methods could be used to determine the validity of results from meta analysis besides conflict of interest?

Based on the answers I've read to a question1 on the Skeptics stack exchange, I began to wonder what methods besides the declaration of industry funding could be used to determine the validity of ...
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1answer
44 views

Help with meta-regression

I want to implement a meta-regression and require some assistance. Suppose that two univariate features ($X$ and $Y$) were measured from two samples $A$ and $B$ of size $N_A$ and $N_B$, respectively. ...
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1answer
42 views

interpreting meta regression results in R

I performed meta-regression in R and got the following results: Mixed-Effects Model (k = 21; tau^2 estimator: ML) ...
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1answer
65 views

Meta-analysis with random effects on prevalence data with > 2 possible outcomes: is it necessary that the weighted prevalences all add up to 100?

I am running a meta analysis on prevalence data. Participants can belong to one of four groups. Each study produces the percentage of participants that belong to each group (e.g., Group A: 50%; Group ...
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1answer
20 views

SMD meta-analysis including cluster-randomised trials: is it possible? If so, how?

Where we have cluster-adjusted results from trials (summary statistics), under what circumstances can we include them in a standardised mean difference (SMD) meta-analysis and which calculations are ...
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0answers
31 views

Effect size calculation for Kruskal-Wallis mean rank test

I have a published paper in which I'm attempting to calculate the effect sizes for various outcomes. For a pre-post scale, the authors report the sample size, mean rank, and p-value for an outcome (...
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27 views

Covariance structure of effects in multivariate meta-analysis with correlated outcomes and predictors

I'm working on a meta-analysis of studies examining the correlation between SES and mental health. Unfortunately, studies typically have multiple measures of both SES and mental health, which I've ...
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26 views

Is it possible to “sample size weight” the effects of multiple regressors to that of a “big” regressor? [duplicate]

I know that you can't just take averages and state that it is the average effect of the big regressor (Simpson's paradox). But I would be interested in knowing wether you could state that a positive ...
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13 views

Checking association between each category of a variable and disease outcome

Suppose a disease can have four different outcomes: Normal, disease_status_1, disease_status_2, and disease_status_3. Let I have two categorical variables in the model: sex (male or female) and age (&...
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0answers
24 views

identifying what has changed in the data year on year

I have a dataset from one year and the 'same' dataset for the next year. I would like to identify what has changed in the datasets between the years. Both datasets have the same columns. I currently ...
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41 views

Meta-analyzing ICCs to avoid using multiple random effects?

(Note: Parts where I've encountered problems are in bold to make them easily findable.) I have data from a longitudinal study of twins. Several biomarkers are measured, usually 4 measurements each (...
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1answer
31 views

Clustering and interactions in a multilevel model in R

We are conducting an individual participant level meta-analysis on a series of clustered randomised controlled trials, where we are mainly interested in an interaction effect with a characteristic (...
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1answer
23 views

d to r conversion for extremely high versus extremely low groups

Context Suppose I am performing a meta-analysis on the relationship between two variables (say depression and life satisfaction). Unfortunately, many studies in the prior literature do not report ...
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28 views

conducting a meta-analysis on pre-post control design studies that use count data

I would like to conduct a meta-analysis on a set of studies that have measured an outcome over a period prior to intervention and post-intervention for a control group and experimental group. A method ...
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13 views

Meta-analysis for case-control studies, confounding factors

Is there a way to adjust the pooled summary effect size (odds ratio) for confounding factors while performing a meta-analysis in R studio? I am performing a meta-analysis and I don't want to pool ...
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1answer
24 views

Re: Random Effect Model in Binomial Proportions Meta-analysis

I have used a random effects model for the meta-analysis of binomial proportions and have encountered several queries. In one meta-analysis, I have four studies. Sample size of 98, 58, 107, 62 ...
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0answers
25 views

How can I calculate z-value from chi-squre distribution with 2 df? [closed]

I tested two models and one is nested inside another. Nested model has 2 parameters and the bigger model has 4. I got the ln likelihood of each models. I know how to calculate the P value using twice ...
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1answer
27 views

Is it possible to calculate standard deviation from d (effect size)? How do you do it?

I am doing a meta-analysis and one of the papers report d instead of SD. I do also have sample size and mean for each group, but I don't have the SD for each group.
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2answers
54 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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0answers
31 views

meta-analysis using metafor pre-post difference without control comparison group

I am conducting a meta-analysis using metafor looking at within subject differences (no control comparison group). My outcome is continuous. This is the syntax I am using: data <- escalc(measure="...
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1answer
105 views

Cohens d from Mixed method model - for the interaction term

I am doing a mixed method model: m1 <- lmer(DV ~ IV*Country + (1+IV:Country|Region), data = data) I am using the lme.dscore to get the Cohen's d for the model....
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1answer
55 views

How to perform a meta-analysis of studies without a control group on metafor?

I am conducting a meta-analysis of studies that didn't use a control comparison group. I use metafor on R. I do have the R code for studies with a control but not without a control. My outcome is ...
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1answer
44 views

Meta-analysis (Metafor) using Cohens D, what is the variance?

I am using the package Metafor in R to do a meta-analysis, my models are derived from lmer (lme4). I am using the package -> EMAtools -> lme.dscore to retrieve the Cohen's d values which will be used ...
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30 views

Multilevel, multivariate meta analysis with dependent effect sizes

I’m doing a meta analysis to find the connection between environmental fluctuation and fitness performance of organisms. I have collected data (844 Hedge’s g mean difference effect sizes ) from 43 ...
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0answers
15 views

Adjusting weights in meta-analyses using R

I am conducting a meta-analysis in R. Some of my studies provide more than one effect size for the same sample. I would like to account for this by adjusting the weight that each within-study effect ...
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0answers
30 views

How to adjust continuous and categorical variables for categorical variable?

I am performing a metaanalysis where I am trying to find predictors for an ordinal response variable. Additionally, I want to perform pair-wise correlations on some of the variables. I have a ...
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0answers
45 views

meta-regression using metafor

How should I syntax the rma function from metafor package in order to get results in the following example? My objective is to compare values (means) among species. I have different papers ...
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0answers
15 views

Meta-analysis pooling an n-of-one study with a (slightly) larger study - can/should it be done?

I'm performing meta-analyses of a continuous measure based on clinical studies. For one subgroup of interest, there are only two studies available: one with n=5 patients and one with n=1 patient. ...
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0answers
25 views

Homogeneity test in survival meta-analysis with adjusted HR

I was wondering what was the way to measure heterogeneity in a survival meta-analysis. I have for each study, an hazard ratio calculated with a penalized cox model (...
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1answer
57 views

Calculating effect size for a study with no groups

I am working on a meta analyisis of the effects of e-learning in an organizational context. I have prepared a list of about 25 studies to analyze and I have organized all the path coefficients based ...
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0answers
25 views

Meta-analysis for case control studies

I am working on a method of meta-analysis for case-control studies by stratifying cases and controls then calculating the effect size. Can I do a meta-analysis including only case-control studies for ...