SAS Support Communities

Luckily all info in the varialbes is accounted for.  So the initial research question was what factors contribute to donationg more or not.  First i looked at each independent variable compared with the dependent varaible and recorded the odds ratio. Then I loaded all of the independet variables in the model and the odds ratios fluctuated from when they were looked at individually vs as a group (attached).  The difference with the odds ratio must be due to all the other variables being in the equation.  But I guess what I'm hung up on is which odds ratio is "right" since there are odds ratios of the logistic regression analysis and odds ratios of comparing individual independent varialbes and the dependent variable.''   Would it be fair to say that the model would be more appropriate because it takes into account 13 other variables which is more "real life" since when making conclusions one should look at many variables?  Looking at just one variable is limiting? ... View more

Using only one variable i obtained a c statistic of .5.  When I included the other 14 variables in my logistic regression model the c statistic increased to .74 which seems to be "good" in terms of the model.  The only issue is that when I did this some odds ratios fluctuated but I'm guessing that has to do with taking into account the other variables in the model?   Example: In the picutre. it shows odds ratio of 2.83 but when added with all the other variables it decreases to 1.12.  Should both numbers be reported? One number being (2.83 - only if you look at this on variable) and (1.12 when you look at all varaibles in the model)? ... View more

So if the C statistic shows that there is no linear relationship then I should still be able to report the odds ratio.  The odds ratio doesn't need to worry about linearity at all correct?  In that case, would it be better to not run a logistic regression model and just manually calculate th odds ratios for each varaiable? ... View more

From the info above my code is the following: Where would the var ref=1 go?  I tired before the i.v.s and after the i.v.s in the first line but it errored. (also I Bolded the variables for clarification purposes)    PROC LOGISTIC DATA=WORK.SORTTempTableSorted PLOTS(ONLY)=ALL ; CLASS BEC (PARAM=REF) "Marital Status"n (PARAM=REF) Gender (PARAM=REF); MODEL Donor (Event = '1')=BEC "Marital Status"n Gender / SELECTION=NONE AGGREGATE SCALE=NONE RSQUARE LINK=LOGIT CLPARM=WALD CLODDS=WALD ALPHA=0.05 ; RUN; ... View more

I went ahead and put it under CLASS with Reference coding style.  In the output it showed the MLEs for only the 0 value. To interpret this would it be the 0 value has a negative estimate which would mean that the 1 value would then be a positive estimate? Just making sure I understand this completely. ... View more