*(Q) Subject: conditional regression
I have matched (on age, sex, and geographic site) data for which I would
like to carry out a conditional regression analysis. Can anyone tell me if
SPSS can run conditional regression analyses? In particular, conditional
logistic regression?
*(A) posted to SPSSX-L on 2002/02/06 by Marta Garcia-Granero.
* This is a more complete answer to your question
* A small dataset to work with *.
DATA LIST LIST /pair(f4.0) exposici (f4.0) outcome (f4.0).
BEGIN DATA
1 0 0
1 1 1
2 0 0
2 1 1
3 0 0
3 1 1
4 0 0
4 1 1
5 0 0
5 0 1
6 1 0
6 0 1
7 1 0
7 1 1
8 1 0
8 1 1
9 1 0
9 1 1
10 1 0
10 1 1
END DATA.
VALUE LABELS exposici
0 "No"
1 "Yes".
VALUE LABELS outcome
0 "Control"
1 "Case".
* Exposici is the IV, outcome is the DV,
* and pair is a variable that matches every case with its control
* (there can be more than 1 control, but ONLY 1 case in each stratum)
* To perform a conditional logistic regression analysis, you need to create
* and extra binary variable "ftime", with values: 1 if subject is case, 2 if
control.
COMPUTE ftime=1+(outcome=0).
EXECUTE.
* Now use COXREG stratifing by the matching variable (pair).
COXREG ftime /STATUS=outcome(1) /STRATA=pair
/METHOD=ENTER exposici
/PRINT=CI(95).
* In the output, "Exp(b)" is the conditional OR you are looking for.