Dear SDM Team,
I am doing a meta-analysis for effect of treatment on a patient population. Many studies include the comparison of patients and healthy controls, though I am interested only in pre and post-treatment effects in patients. So when I prepare the table should I report the total sample of patients or just the smaller sample which responded to the treatment(for pre and post comparison).

Thanks!

Dear ,

if the studies perform the pre-post comparison only using the patients (i.e. comparing the activation in patients before vs. after the treatment), controls are not used and thus their sample sizes must not be specified. Otherwise, if the studies perform the pre-post comparison using the controls (i.e. comparing the difference between patients and controls before vs. after the treatment), controls are used and thus their sample sizes must be specified.

Hope this helps,

Joaquim