Robust Semiparametric Analysis
------------------------------

The PHREG Procedure

        Model Information

Data Set                 WORK.RATS
Dependent Variable       start    
Dependent Variable       stop     
Censoring Variable       status   
Censoring Value(s)       0        
Ties Handling            BRESLOW  

Number of Observations Read         254
Number of Observations Used         254

Summary of the Number of Event and Censored Values
 
                                     Percent
   Total       Event    Censored    Censored

     254         212          42       16.54

                       Convergence Status

         Convergence criterion (GCONV=1E-8) satisfied.          

         Model Fit Statistics
 
                 Without           With
Criterion     Covariates     Covariates

-2 LOG L        1633.647       1601.960
AIC             1633.647       1603.960
SBC             1633.647       1607.317

          Testing Global Null Hypothesis: BETA=0
 
Test                    Chi-Square       DF     Pr > ChiSq

Likelihood Ratio           31.6869        1         <.0001
Score (Model-Based)        30.5430        1         <.0001
Score (Sandwich)           11.2031        1         0.0008
Wald (Model-Based)         28.9017        1         <.0001
Wald (Sandwich)            16.9789        1         <.0001

                   Analysis of Maximum Likelihood Estimates
 
               Parameter    Standard  StdErr                            Hazard
Variable  DF    Estimate       Error   Ratio  Chi-Square  Pr > ChiSq     Ratio

trt        1    -0.81638     0.19812   1.305     16.9789      <.0001     0.442