Yes the results was exactly as indicated in the book. However, the
Wald test of the fixed effects of GROUP or TIME are not exact. I have
only been able to reproduce the interaction effects as seen below:
. test _IgroXtim_1_0 _IgroXtim_1_1 _IgroXtim_1_4
( 1) [lead]_IgroXtim_1_0 = 0
( 2) [lead]_IgroXtim_1_1 = 0
( 3) [lead]_IgroXtim_1_4 = 0
chi2( 3) = 107.79
Prob > chi2 = 0.0000
The group effect should have 1 degree of freedom with chi-sq = 25.43
The time effect should have 3 degrees of freedom with chi-sq = 184.48
Raphael
On Tue, Jan 6, 2009 at 7:44 AM, Joseph Coveney <[email protected]> wrote:
> Raphael Fraser:
>
>> Thank you Joseph. I was trying to reproduce the results in Garrett
>> Fitzmaurice book, Applied Longitudinal Analysis p.116-7 Tables 5.3-5.5
>>
>
> It's the same dataset (lead concentrations in blood of children treated with
> a
> chelating agent) and SAS code, so the do-file that I posted should reproduce
> the results in _Applied Longitudinal Analysis_ exactly. I don't have the
> book, so let me know if it doesn't.
>
> Joseph Coveney
>
>
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>
--
Raphael A. Fraser, MSc
Lecturer in Biostatistics
Tropical Medicine Research Institute
Faculty of Medical Sciences
University of the West Indies
Mona Campus
Kingston, JAMAICA
Tel: (876) 927-2471; 977-6151
Mobile: (876) 410-4699
Fax: (876) 927-2984
e-mail: [email protected]
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