Hello,

you want to conduct a meta-analysis on SMD (Cohen). well, if primary studies reported SMD you extract them. If studies did no report them, you still can calculate them from sample size(N), mean(M) and standard deviation(S) of case (exposure or intervention) group and control group, respectively. In other words, you should extract N1, M1, S1, N2, M2 and S2 from each primary study. using these six data you can conduct a meta-analysis on Cohen's d (SMD) because these six data give you or calculate SMD of each primary study.

This section "3.3.1.2 Between-Group Standardized Mean Difference" of the following link maybe useful

https://bookdown.org/MathiasHarrer/Doing_Meta_Analysis_in_R/effects.html

I recommend "Handbook of meta-analysis in ecology and evolution" by Gurevitch and Koricheva (quite broad in spite of field-specific title). In short - if your cohen's d is SD standardised you can use it together with its sampling variance in the model. If you want to mix d with other effect size measures (e.g., correlation) you will have to transform all into Fisher's Z.