This question is not related to any example in particular - it is more like a "methodological" matter, which I feel may be useful to discuss.
If we are conducting a meta-analysis on the comparative efficacy of two treatment, we can do two different things:
- Meta-Analyze the number of events and total number of patients in each group
- Meta-Analyze the log-adjusted summary data that comes from the original studies included (i.e., adjusted Hazard Ratio, or adjusted Odds Ratio).
While the former method is more "straightforward", one can question about the opportunity to combine non-adjusted data from different studies - so using the adjusted HR/OR would be better.
On the other side, I already know that we cannot easily combine together logHR and logOR (they are not interchangeable). But what are the other caveats to this approach?