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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Calculating variance from standard error of pearsons r correlations z scores [duplicate]

I understand that to calculate the standard error of a pearsons r correlation converted to a z score you follow - 1 / (√N−3) But how do you calculate the variance from the standard error please? I ...
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152 views

Independent & non independent effect sizes/correlations for meta analysis

I am conducting a meta analysis of pearsons r correlations and would like to double check my understanding of independent and non- independent effect sizes/correlations. Am I correct in understanding ...
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825 views

can you transform spearmans r into pearsons r for meta analysis

my meta analysis involves the calculation of overall effect size based on pearsons r correlations within studies. I am already converting the pearsons r to fishers z scores for analysis but I have a ...
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197 views

Z-value in R using the Eggers test. How to get the t-value

I am currently conducting a meta-analysis using R for my masterthesis. To test for publication bias I ran the Eggers test. In the output I get a z-value, however in all the published meta-analysis ...
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Meta-analysis of proportions - how to analyze possible moderators and publication bias?

I am performing a meta-analysis study of proportions in Stata using the metaprop command. My data includes 10 studies for which I have the variables: ...
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74 views

Effect size calculation

I am conducting a meta-analysis on the diet of predators. This diet is expressed as the proportion of aquatic vs terrestrial prey. I have a value (% of aquatic prey) for each species for each site of ...
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102 views

tau2 estimation using reml in SAS

I would like to obtain tau2 estimation using REML by making use of PROC MIXED procedure in SAS to compare the estimation result obtained from rma function in R. I have used the following SAS code; ...
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42 views

Standard error of the mean of two estimates

I have been googling for a while to find an answer to this question. I am sure there is plenty of information somewhere but, I don't know why, I really can't find it. Suppose that you have two ...
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400 views

What is the variance of log response ratio when adding a constant to the means?

Note: while I asked if is ok or not to add a constant to the log response ratio here, with this question I focus specifically on the formula of the variance of the log response ratio when adding a ...
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How would I conduct a relative risk meta-analysis, when the exposure levels in the data are presented in overlapping ranges?

For example, if I have studies observing the dose-response relationship between alcohol (g/day) and breast cancer, and the exposures are reported as heterogeneous and overlapping ranges (10-20g, 15-...
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46 views

How should I approach statistically?

I am conducting a meta-analysis on the therapeutic benefits of drug A - treated vs placebo. I would like to address the possibility of side effects/tolerability/likeliness of developing side effects. ...
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80 views

Random Effect Model or Fixed Effect Model in meta-analysis? [duplicate]

I am investigating the prophylactically effect of drug A regarding onset of epileptic seizures. Drug A is given to the test group and not the control group. The hypothesis is that drug A does not ...
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130 views

Calculating effect size and post-hoc power from mean difference in a meta-analysis

I wish to calculate the power of each included study to detect the "true" treatment effect. For pregabalin the mean difference is -33.14. As far as I understand one way to achieve this is to calculate ...
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132 views

Change Rcode for a meta-regression model of a meta-analysis to use a random effects model instead of a mixed effects model

I am writing a meta-analysis that compares the complication rates and reoperation rates of 5 treatment modalities after a distal radius fracture by metaregression. But the metaregression uses a mixed ...
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37 views

Meta analysis using the effect size based on mean and multiple outcomes [duplicate]

I have few questions on the meta analysis. First, the data is longitudinal and according to the CMA (comprehensive meta analysis) guidebook "Working with more than two outcomes per study The formulas ...
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31 views

How to reduce subjectivity in the Baseline Inequality Index for meta-analysis

I have recently come across an interesting means to appraise baseline differences in competing groups in clinical trials being pooled for meta-analysis: the Baseline Inequality Index. As far as I am ...
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27 views

How could one derive power indicators for omnibus tests?

A while ago I posted a question regarding performing post-hoc power analyses in meta-analyses and was given a couple of useful links to discussions regarding why this isn’t a good idea. From my ...
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726 views

Linear regression from two meta-analysis outcomes in R metafor

First of all, I am sorry if this question sounds very basic, but I am new in meta-analysis and statistics and I don’t know how to execute what I have in mind. I have a dataset of 60 experiments with ...
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30 views

Predicting a parameter using the estimates of a series of studies, using study location and year as random effects

I would like to ask whether my analysis design is correct. I gathered all the trials on a series of drugs for a certain condition (second line therapy for advanced/metastatic lung cancer), published ...
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135 views

Effect of ignoring correlation between studies providing data for multiple comparison on the meta-estimate

I am addressing reviewer comments on a meta-analysis paper I performed on mean gastric pH in fed and fasted states. Some literature studies included in the meta-analysis provided data for multiple ...
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314 views

Repeated-measures meta-analysis with adjusted post-test means

I am conducting a meta-analysis over pre-test to post-test scores. To this end, I calculate Cohen's d with the following formula: ...
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1answer
195 views

Comparing rates of success in paired groups of samples

I have $2n$ paired populations, on which I measure a rate of success, let's say $(r_{group}^i)_{group \in (0,1)}^{i \in[1,n]}$ where $r_0^i$ and $r_1^i$ are the rates of success in the $i$-th pair of ...
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866 views

Determining variance of meta-analysis log-response ratio generated from fitted curve

I'm working on a meta-analysis and have generated a quirky question for which I'm at a bit of a loss. The MA is for a large set of factorial experiments. Calculating the Log Response Ratio (LRR) and ...
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86 views

Controlling for baseline differences?

I am comparing two groups, with data before and after retirement, to see the effect retirement has on depression levels. The control group works over the two measurement points, and the retirees ...
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763 views

Is Cohen's $d$ a better measure of effect-size than a simple mean difference for a meta-analysis?

Cohen's $d$ measures the difference between the mean for the experimental group and the control group divided by standard deviation. The Cohen's $d$ statistic produces something that does not add any ...
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Hazard Ratio Meta-Analysis

I've being reading around the forum and couldn't find exactly what I wanted. I am trying to do an meta-analysis where the HR of each study and the 95% CI were available. I understand variance can be ...
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965 views

Confidence intervals and meta-analysis

I've heard that meta-analytical needs are actually a good argument for using confidence intervals in most applicable figures. Could someone explain this to a non-statistician? I suppose it has ...
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257 views

Meta Analysis - Importance of significance levels of included studies

How important should the significance level be in the decision process to include single results in a Meta-Analysis? In a Meta-Analysis of different studies some of the included studies describe ...
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What are key differences between homoscedasticity of effect-sizes and homogeneity of variance?

The terms - Homoscedasticity and homogeneity of effect-sizes are frequently used with respect to regression analysis/ Anova.These assumptions create lot of confusion at least in my mind. I am not ...

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