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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 specified
factors and covariates. A separate set of odds ratios is computed for each category of the
dependent variable except thereference category.
Factors. For each selected factor,displays the ratio of the odds at each category of the factor to
the odds at the specified reference category.
Covariates. For each selectedcovariate, displays the ratio of the odds at the covariate’s mean value
plus the specified units of change to the odds at the mean.
When computing odds ratios for a factor or covariate, the procedure fixes all other factors at their
highest levels and all other covariatesat their means. If a factor or covariate interacts with other
predictors in the model, then the odds ratiosdepend not only on the change in the specified
variable but also on the valuesof the variables with which it interacts. If a specified 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.