[R] Adjusting confidence intervals for paired t-tests of multiple endpoints
Erich Studerus, Psychiatrische Uni-Klinik
erich.studerus at bli.uzh.ch
Sun Mar 1 14:14:33 CET 2009
Johannes Huesing <johannes at huesing.name> wrote:
> Couldn't you re-phrase your model by including timepoint as a continuous
> regressor and scale as a factor?
Well, the measuring time points are 70 170, 300 and 1440 minutes after drug
intake. Since the influence of time is cerainly not linear, I think it's
better to treat it as categorical factor. In fact, I already calculated
mixed effects models with the four-level factor time and the two-level
factor treatment and random effects factors subjects (nested in studies) and
studies for each scale. I used mixed effects models, because I'm doing a
meta-analysis on the raw data of 8 studies. Thus my dataset has not only a
grouping structure, but is also unbalanced (not all studies did 4
measurements). I'm not sure, if I could extend my model by including another
factor for scale, since these scales measure quite different things. I
guess, It would be also very difficult the set up appropriate contrasts to
compare each scale on each measuring time point.
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