[R-meta] Calculating SMD from posttest only - is this possible?

[Guido Schwarzer]

Hi Roberto,

Just to add to the responses by Wolfgang and James.

The Cochrane Handbook warns against combining SMDs based on change 
scores (pre-post comparisons) and post-test comparisons (see 
https://training.cochrane.org/handbook/current/chapter-10#section-10-5-2). 
The reason is that the standard deviation used in the denominator of the 
SMD is different for change scores and post-tests.

Best wishes, Guido

-- 
Dr. Guido Schwarzer
Institute of Medical Biometry and Statistics,
Faculty of Medicine and Medical Center - University of Freiburg

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