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st: repeated factor ANOVA


From   James prince <jsprince26@gmail.com>
To   statalist@hsphsun2.harvard.edu
Subject   st: repeated factor ANOVA
Date   Tue, 2 Oct 2012 07:57:07 -0500

Hello,

I am unsure how to set-up the following problem using the ANOVA
command. Any help would be appreciated.

I have data on 600 liver patients, 300 assigned to one of two
treatment groups (TREAT).
Each had 4 biopsy (one in each quadrant: UR, UL, LR, LL) and the
concentration on an enzyme (Y) measured. I also have data for sex. I
know that I can used XTMIXED to do this, but I need to use ANOVA

Thank you in advance,
Jim

--------------------------------------------------------------------------------------

This is what I did:  I first tried using a repeated ANOVA but got an error:

. anova y treat liver sex subj, repeat(subj)
could not determine between-subject error term; use bse() option

Then,
If I set it up as nested, I get a result, but I am not sure if it is correct.
anova y treat liver sex/ subj|liver/

                           Number of obs =     696     R-squared     =  0.7757
                           Root MSE      =  2.7219     Adj R-squared =  0.5508

                  Source |  Partial SS    df       MS           F     Prob > F
              -----------+----------------------------------------------------
                   Model |  8892.14113   348  25.5521297       3.45     0.0000
                         |
                   treat |  .032965724     1  .032965724       0.00     0.9670
                   liver |  2235.41594     3  745.138647      38.76     0.0000
                     sex |  .048400013     1  .048400013       0.00     0.9600
              subj|liver |  6593.27098   343  19.2223644
              -----------+----------------------------------------------------
              subj|liver |  6593.27098   343  19.2223644       2.59     0.0000
                         |
                Residual |  2570.83017   347  7.40873248
              -----------+----------------------------------------------------
                   Total |  11462.9713   695  16.4934839

--------------------------------------------------------------------------------------------------------------
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