Parameters | Clinical | Class Variables

Class Variables
Specify one or more variables whose levels form distinct categories in the model, in this field.
List all variables whose levels form distinct categories in the model in the Class Variables field. Indicator variables are created for each level of each variable. If you do not specify an effect, then the numerical values of the variables are used directly in the model as in linear regression.
Note: The order in which you specify class variables determines how LSMeans and/or interaction effects are sorted.
This option is available only when the Response Type is an incidence density.
To Specify Class Variables:
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Make sure that either Incidence density based on first event only or Incidence density based on all events is selected as the Response Type.
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Highlight variable(s) from the Available Variables field. To highlight multiple variables at once, hold down Ctrl while left-clicking on them.
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Click to add the highlighted variable(s) to the Class Variables field, as shown below:
Refer to the SAS PROC GLIMMIX documentation for more information.