MODEL (t1, t2)= effects </ options>;
The MODEL statement identifies the variables to be used as the failuretime variables and the explanatory effects, including covariates, main effects, interactions, nested effects. For more information, see the section Specification of Effects in Chapter 46: The GLM Procedure.
The MODEL syntax specifies two variables, t1 and t2, that contain values of the endpoints of the censoring interval. Only nonnegative values are accepted. If the two values are the same (and not missing), it is assumed that there is no censoring and the actual response value is observed. If the lower value is missing, then the upper value is used as a leftcensored value. If the upper value is missing, then the lower value is used as a rightcensored value. If both values are present and the lower value is less than the upper value, it is assumed that the values specify a censoring interval. If the lower value is greater than the upper value or both values are missing, then the observation is not used in the analysis.
The following table summarizes the ways of specifying censoring.
Lower Value 
Upper Value 
Comparison 
Interpretation 


Not missing 
Not missing 
Equal 
No censoring 

Not missing 
Not missing 
Lower < upper 
Censoring interval 

Missing 
Not missing 
Upper used as left 

censoring value 

Not missing 
Missing 
Lower used as right 

censoring value 

Not missing 
Not missing 
Lower > upper 
Observation not used 

Missing 
Missing 
Observation not used 
Table 63.5 summarizes the options that you can specify in the MODEL statement.
Table 63.5: MODEL Statement Options
Option 
Description 

Model Specification Options 

Specifies the confidence level 

Specifies the functional form for the baseline function 

Specifies the lefttruncation time of the model 

Suppresses polishing of parameter estimates of the hazard function 

Specifies an offset variable to be added to the linear predictor 

Requests parameterization of the hazard function in the original scale or in log scale 

Output Options 

Displays the estimated correlation matrix 

Displays the estimated covariance matrix 