meta-analysis

  1. T

    Multiple Meta-Regression in Stata Help

    I'm new to meta-analysis and to Stata. I understand how to use the user interface to insert multiple covariates into a meta-regression. However, I am not sure how to interpret the output and to make sure that the software has controlled for multiplicity and covariate correlation - so that I...
  2. R

    Looking for the appropriate stat test

    I am attempting to do a meta-analysis to understand a treatment effect . There are groups across many studies which have treatments A and B and a control group without any treatment. In other studies, there are groups with just treatment A and control groups. I am trying to understand what the...
  3. F

    Questions about trial sequential analysis for non-randomized control studies (non-RCTs)

    May I ask a question on the trial sequential analysis (TSA)? It is a method of cumulative meta-analysis. Could we pooled adjusted risk ratios (aRR) in trial sequential analysis, especially for observational studies in which there are obvious differences between crude RR and adjusted RR? Now, I...
  4. E

    OR meta-analysis using R

    Hi! I have currently been using MedCalc for Odds Ratio meta-analysis. For both intervention and control groups is required the following data input: number of positive cases and number of total cases. The problem is, sometimes studies report Odds Ratios with CI:s, without primary data. ORs...
  5. T

    Change of statistical significance when excluding heterogenic studies?

    Hi all, I have performed a meta-analysis and found a certain pooled effect with 95% CI that was not statistically significant (p>0.05). Consequently, I have done a sensitivity analysis for which I have excluded studies that contributed most to heterogeneity. In order to do so I used the...
  6. S

    Likelihood ratio or wald test for meta-analysis

    Hi there! This is my first time posting but I've always been a frequent lurker on previous posts that have been super helpful, so apologies if I'm not following any appropriate etiquette. I am working on an RNA sequencing project and looking have different outputs, which provides either a...
  7. M

    Individual results in forest plot meta-analysis

    Dear all, In this meta-analysis (https://www.ncbi.nlm.nih.gov/pubmed/30475963) it seems that for instance in figure 2 for lean body mass improvements individual studies did not find significant better results with protein supplementation compared to no protein supplementation (since the...
  8. N

    Meta-analysis and longitudinal studies with baseline differences across two groups.

    I have a question on what meta-analysis is best when aggregating means using non-randomized longitudinal data with a control group that significantly differs from the active group at baseline. The outcome in question is depression, and the question is whether depression scores soar or fall in...
  9. L

    Meta-analysis with dependent samples

    Dear Forum, for my thesis I would like to conduct a meta-analysis with the aim to summarize the findings about the effectiveness of a political measure. The corresponding studies compare countries in which the measure was implemented with countries in which it was not implemented and calculate...
  10. B

    Heterogeneity calculation based on odds ratios and confidence intervals

    Hi, I wonder if you might be able to help with testing for heterogeneity (Cochran's q or I-squred) in meta-analysing genotypic odds ratios in two groups from two different genetic associations studies of the same phenotype. (This question pertains to genetics, but the principle, I believe, is...
  11. P

    Trial sequential analysis of noninferiority randomized control trials

    Hello, anyone out there familiar with Trial Sequential Analysis (TSA) software developed by Copenhagen Trial Unit? The free software is available at: http://www.ctu.dk/tsa/downloads.aspx Manual is available here: http://www.ctu.dk/tsa/files/tsa_manual.pdf Summary of my questions up here: 1. How...
  12. L

    Converting spearmans r to fishers z for meta analysis ; Correcting for range in meta analysis

    Hi all I am conducting a meta analysis of pearsons r correlations but I have a study with a spearmans rank correlation. I was converting the pearsons correlations into fishers z scores to conduct the meta analysis , then to be converted back into correlations, but I am wondering if I am able to...
  13. J

    Meta-analysis using revman

    I was wondering if someone can help me with a meta-analysis using revman 5.3. I would like to switch from quadas to quadas2 but this link seems to be missing from the General tab. Has anyone had the same problem?
  14. A

    What statistical techniques to apply when comparing cronbach's alpha in a Meta-analysis

    I am doing a meta-analysis in which I am comparing 3 outcomes measures across multiple studies: (1) Cronbach's alpha (2) Kappa coefficient or Interclass correlation coefficient (depending on which study chose what measure) (3) Spearman Rank Correlation coefficient or Pearson correlation...
  15. B

    Effect Size - Cohen's D calculation

    I had a question about how to calculate Cohen's D a particular situation for my meta-analysis. I am a first year grad student, so my familiarity with statistics is somewhat limited! The study design - participants are assigned to one of two groups (parallel design), but not a true RCT because...
  16. A

    Meta-analysis for Pre vs Post (Which SD to use)

    Hello everyone, I have extracted data from longitudinal studies that have collected data on pre and post time points. All studies have same time period. So I have got N_pre Mean_Pre SD_Pre N_post Mean_Post SD_Post In order to compute the standardised or unstandardised Mean...
  17. K

    Use treatment effect as input for meta-analysis, not 2 groups

    Hey, I'm new to R and currently trying to teach myself how to use it with various guides. Problem is, none of the guides cover the scenario I'm dealing with, they all assume that for a meta-analysis you have outcome data for both the control and treatment groups. I would like to use the...
  18. S

    meta-analysis vs. random effect combined analysis

    I have data from 200 similar studies, all measuring the same effect of a continuous independent variable on the same continuous response. I say similar because the designs are different (split plot vs. rcbd) and the levels of the independent variable is not the same across all studies. I have...
  19. C

    Meta-analysis - Can I investigate mediation effects for the effectiveness of training

    Hello everyone, I am currently working on my Master thesis on moderators and mediators for the effectiveness of cross-cultural training (CCT). I am actually writing a literature review, but want to end my thesis by judging to what extent the included studies could also be compared...
  20. A

    Adjustment for correlated data in meta-anlaysis

    Hi, I'm completing a systematic review and performing meta-anlaysis forest plots. The research question related to the finding of risk factors for a complication of diabetes. There are therefore many different risk factors and often there are only three papers with similar...