IBM SPSS COMPLEX SAMPLES 19 Water System User Manual


 
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Chapter 10
Complex Samples Logistic Regression Odds Ratios
Figure 10-6
Logistic Regression Odds Ratios dialog box
The Odds Ratios dialog box allows you to display the model-estimated odds ratios for specied
factors and covariates. A separate set of odds ratios is computed for each category of the
dependent variable except the reference category.
Factors. For each selected factor, displays the ratio of the odds at each category of the factor to
the odds at the specied reference category.
Covariates. For each selected covariate, displays the ratio of the odds at the covariate’s mean value
plus the specied units of change to the odds at the mean.
When computing odds ratios for a factor or covariate, the procedure xes all other factors at their
highest levels and all other covariates at their means. If a factor or covariate interacts with other
predictors in the model, then the odds ratios depend not only on the change in the specied
variable but also on the values of the variables with which it interacts. If a specied covariate
interacts with itself in the model (for example, age*age), then the odds ratios depend on both the
change in the covariate and the value of the covariate.