[R] Adjusting confidence intervals for paired t-tests of multiple endpoints

Dieter Menne dieter.menne at menne-biomed.de
Sat Feb 28 18:41:11 CET 2009

Erich Studerus <erich.studerus <at> bli.uzh.ch> writes:

> Dear R-users,
> In a randomized placebo-controlled within-subject design, subjects recieved
> a psycho-active drug and placebo. Subjects filled out a questionnaire
> containing 15 scales on four different time points after drug
> administration. In order to detect drug effects on each time point, I
> compared scale values between placebo and drug for all time conditions and
> scales, which sums up to 4*15=60 comparisons.
> Now, I want to adjust the confidence intervals for multiple comparisons.

For simple cases, see p.adjust or TukeyHSD (more limited).

For complex cases, see simint and friends in package multcomp.


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