Major difference in the outcome between SPSS and R statisticalprograms

First off, Marc Schwartz posted this link earlier today, read it.

http://cran.r-project.org/doc/FAQ/R-FAQ.html#Why-are-p_002dvalues-not-di
splayed-when-using-lmer_0028_0029_003f

Second, your email is not really descriptive enough. I have no idea what
OR is, so I have no reaction.

Third, you're comparing estimates from different methods of estimation.
lmer will give standard errors that account for the correlation of
individuals within similar units whereas the SPSS procedure will not.
The lmer standard errors better capture the true sampling variance of
the parameters and SPSS doesn't.

-----Original Message-----
From: Draga, R. [mailto:R.Draga at umcutrecht.nl]
Sent: Friday, August 01, 2008 11:45 AM
To: Doran, Harold
Subject: RE: [R] Major difference in the outcome between SPSS
and R statisticalprograms

Thanks for the reaction

I know, I would not expect the outcomes to be the same.
But, I have never before encountered such a difference in
outcomes between SPSS and R; mostly the OR's and p-values
differed a little bit.

Strange is that R shows a OR of 10,176 and 95% CI of
6,295-14,056. Then the p-value must be <0.05 doesn't it?
For age the OR's differ dramatically between SPSS and R,
0.985 and 0.003.

I just can not explain it.

Ronald

-----Oorspronkelijk bericht-----
Van: Doran, Harold [mailto:HDoran at air.org]
Verzonden: vrijdag 1 augustus 2008 17:36
Aan: Draga, R.; r-help at r-project.org
Onderwerp: RE: [R] Major difference in the outcome between
SPSS and R statisticalprograms


The biggest problem is that SPSS cannot fit a generalized linear mixed
model but lmer does. So, why would you expect the GLM in SPSS and the
GLMM in lmer to match anyhow?

-----Original Message-----
From: r-help-bounces at r-project.org
[mailto:r-help-bounces at r-project.org] On Behalf Of Draga, R.
Sent: Friday, August 01, 2008 10:19 AM
To: r-help at r-project.org
Subject: [R] Major difference in the outcome between SPSS and
R statisticalprograms

Dear collegues,

I have used R statistical program, package 'lmer', several
times already.
I never encountered major differences in the outcome between
SPSS and R.
...untill my last analyses.

Would some know were the huge differences come from.

Thanks in advance, Ronald

In SPSS the Pearson correlation between variable 1 and
variable 2 is 31% p<0.001.



In SPSS binary logistic regression gives us an OR=4.9 (95% CI
2.7-9.0), p<0.001, n=338.

                    OR          lower   upper

gender          1,120       0,565   2,221

age               0,985       0,956   1,015

variable 2         4,937   2,698   9,032



In R multilevel logistic regression using statistical

package 'lmer'

gives us an OR=10.2 (95% CI 6.3-14), p=0.24, n=338, groups:

group 1,

98; group 2 84.

                   OR           lower   upper

gender         2,295        -2,840 7,430

age              0,003        -70,047           70,054

variable 2     10,176     6,295   14,056



The crosstabs gives us:

     variable A

Var B  0   1

    0 156 108

    1  17  57



Would somebody know how it is possible that in SPSS we get
p<0.001 and in R we get p=0.24?


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