I am primarily a clinician, but am busy writing a systematic review and meta-analysis of certain medication trials and was wondering if there might be a simple solution to the problem I am facing.

Essentially, I am trying to infer data from other published data. The paper in question presents means and standard deviations of outcome data for adults and children combined, as well as for adults only. Is there any way to infer the mean and standard deviations for children only?

For example for adults and children combined the mean (SD) = 11.5 (6.8) with n = 17

For adults only the mean (SD) = 12.5 (6.3) with n = 14.

Is there any way to calculate the mean (SD) for the remainder of n = 3 (ie the children by themselves)?

My intuition is that there is likely a fairly simple way to do this?

I am able to infer the missing mean through basic algebra, but the standard deviation I am not sure of.

Thank you for any input!

Kindly,

Jacob