The metafor website gives a number of examples for how to conduct meta-analyses with OR data: http://www.metafor-project.org/

You should be able to have those examples guide your own analysis. But first you should decide exactly what you are asking in your meta-analysis. Is there an overall average OR between studies? Or are you interested in explaining variation in the OR among studies? Or testing for publication bias?

You should also make sure that your collection of studies has been drawn systematically from the literature, as opportunistic collection of studies can lead to a huge potential for bias.

I don't want to be pedantic, but I would probably be careful in your report not to refer to this as "correlation meta-analysis" because some will argue that the term "correlation" should be reserved for when you are looking at Pearson's or Spearman's correlation, for example.

Are these randomized controlled trials in your meta-analysis? If not, also be careful not to imply that you can tell if the factors "affect" any outcomes. Only randomization can answer the question of causality.

Other than, standard advice for any meta-analysis applies, including some of the points Daniel makes above, e.g. a systematic literature search, exploration of heterogeneity, etc. 

Dear Denny

Analyzing relationship between factors that potentially could affect an outcome depends on what kinds of data you could extract from selected studies for review. If considered factors are the main factors of the studies you should first calculate standardized effect size based on the extracted data and then use Inverse Variance method to obtain the pooled estimate. If they are not the main factors of the studies, the effect of those factors should be estimated by multivariate regression type analysis so that you can adjust the effect of other variable and obtain more accurate results.

If you need more help you can contact:

[email protected]    or

[email protected]

Regards

Armin

Dear Armin

Much thanks.I found the below as part of my review. Will definitely get back in case any help is needed.

http://cebcp.org/practical-meta-analysis-effect-size-calculator/

http://www.ncbi.nlm.nih.gov/pubmed/14664682

regards

Denny

Dear Denny

The links you found are very helpful. thank you for introducing them to me.

regards

Armin

Dear Danny, Thanks for the links. That is indeed useful for quick reference. However, the theory need to be understood.

Regards

if you are finding difficulties in conducting meta-analysis with R.....you can use window software meta-win, it is really simple.