S×F vari­­ance: Followup [General Sta­tis­tics]

posted by AngusMcLean – USA, 2015-02-02 18:22 (3364 d 14:49 ago) – Posting: # 14355
Views: 38,292
(edited by AngusMcLean on 2015-02-02 22:16)

❝ ❝ John: You have 71 subjects (69 df) for Wt: I have 69 subjects (67 df) ......the 2 subjects you include in SAS and I exclude in Phoenix are 24 and 31. So the question arises what are the rules in your code that allow you to include them in SAS.

❝

❝ Before we proceed. Are you in agreement with my subject listing for Dlatr and ilat? I looked at Dlatt (wt) listing and the SAS dataset and noted the following:

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❝ Subject 24 only has TTR (missing one R), and subject 31 has RTT (missing one R). Why would Winnonlin drop these two subjects? Both have 2 Ts and hence Dlatt should've been calculated just like the rest of the qualified subjects.

❝

❝ John

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❝ P.S. I am still waiting for Helmut's response the H and u calculations...


John: Thank you. The only difference was in the WT result. What helped me out was you gave me the listing you used for WT. Because you used subject 24 and 31 then that gave me the clue as to how to modify the Phoenix workflow to get the same result (and correct one) agreeing with your (and Helmut's results). The subjects with replicate values available for T (e.g 24, 31) are now included since I modified the transformation criteria to accept subjects with replicate T values. Also the calculation is now for test ratios not reference. I did not bother about using a copy of "Prepare Data Sets for Analysis ..." I modified the standard one that comes with the worksheet and I got almost identical results (WT 0.1165394 and Chi 89.391268 to Helmut). I have a spreadsheet in Excel that does the next steps (my results below). I did round my values to 4 decimals (should have used them all).
H σ2D = ΣEQ + (ΣU)1/2 =0.06696. I can send you the spreadsheet if you like: it is set up like the Guidance and you can check-confirm the steps sequentially. Alternatively send me the values you have for the variance parameters (with you decimals) and I will calculate the final steps in the spreadsheet sequentially. If I assume your prior values are still current
Par dfd    Var(σ2)        Cinv
WT   69  0.116539674     89.39120787
WR   71  0.199313551     91.67023918
WI   67  0.165897781     49.16227018
Then I get:
σ2D =σ2I-0.5*(σ2wt + σ2wr)= 0.00798
and
H σ2D = ΣEQ + (ΣU)1/2 =0.06692

Note: my value for H1 (MI) is 0.11305 and uses CHi value of 49.16227018; it is smaller than your value since CHI (p=0.05) is 49.16227018

Angus

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