I am trying to analyze my data using Multinomial Logistic Regression whereby my dependent variable is a clinical outcome (sick vs healthy) and 1 independent variables (Factors) are in several categories.
The problem I have is trying to figure out how I can set one of the category as a reference group in SPSS.
I have done the inverse analysis by switching dependent and factor variables so I can set the reference but after now that I think about it, I realize it doesn't make much sense. I also compared the OR values from MLR to that of a 2x2 analysis but it is vastly different.
I also tried Binary Logistic Regression and created dummy variables for each category but I didn't have sensible values either.
EDIT: SPSS command and output [I have set the first category (1) in my independent variable as reference]
NOMREG Group (BASE=FIRST ORDER=ASCENDING) BY Status /CRITERIA CIN(95) DELTA(0) MXITER(100) MXSTEP(5) CHKSEP(20) LCONVERGE(0) PCONVERGE(0.000001) SINGULAR(0.00000001) /MODEL /STEPWISE=PIN(.05) POUT(0.1) MINEFFECT(0) RULE(SINGLE) ENTRYMETHOD(LR) REMOVALMETHOD(LR) /INTERCEPT=EXCLUDE /PRINT=PARAMETER SUMMARY LRT CPS STEP MFI.