In Stata terms,
gen diff = y - x
su diff
di r(mean) / r(sd)
Nick
[email protected]
James Shaw
> The standardized response mean (SRM) is one of several
> available effect size indices used to gauge the
> responsiveness of scales to clinical change. The SRM
> is computed by dividing the mean score change (i.e.,
> follow-up minus baseline) by the standard deviation of
> the change. Other effect size indices use the
> standard deviation at baseline (Cohen's D) or the
> standard deviation for clinically stable individuals
> (responsiveness statistic) in the denominator.
>
> The independent groups' t statistic can be used as an
> index of responsiveness in trials comparing treatment
> with control. One simply divides the difference in
> change scores between treatment groups by the standard
> error of the difference between the group means.
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