例16-02计算结果.lst

SAS应用_医学统计学的例题程序及其结果,学习SAS的必备资料.

                                       The SAS System        21:18 Tuesday, April 2, 2002  17

                                   The LOGISTIC Procedure

           Data Set: WORK.EX16_2
           Response Variable: Y
           Response Levels: 2
           Number of Observations: 54
           Link Function: Logit


                                       Response Profile

                                  Ordered
                                    Value       Y     Count

                                        1       0        26
                                        2       1        28



                                Stepwise Selection Procedure


Step  0. Intercept entered:


                     Residual Chi-Square = 25.4181 with 8 DF (p=0.0013)



Step  1. Variable X6 entered:


             Model Fitting Information and Testing Global Null Hypothesis BETA=0

                                      Intercept
                        Intercept        and
          Criterion       Only       Covariates    Chi-Square for Covariates

          AIC              76.786        67.467         .
          SC               78.775        71.445         .
          -2 LOG L         74.786        63.467       11.319 with 1 DF (p=0.0008)
          Score              .             .          10.117 with 1 DF (p=0.0015)


                     Residual Chi-Square = 18.0210 with 7 DF (p=0.0119)



Step  2. Variable X5 entered:

                                       The SAS System        21:18 Tuesday, April 2, 2002  18

                                   The LOGISTIC Procedure

             Model Fitting Information and Testing Global Null Hypothesis BETA=0

                                      Intercept
                        Intercept        and
          Criterion       Only       Covariates    Chi-Square for Covariates

          AIC              76.786        61.480         .
          SC               78.775        67.447         .
          -2 LOG L         74.786        55.480       19.306 with 2 DF (p=0.0001)
          Score              .             .          16.470 with 2 DF (p=0.0003)


                     Residual Chi-Square = 12.6159 with 6 DF (p=0.0496)



Step  3. Variable X8 entered:


             Model Fitting Information and Testing Global Null Hypothesis BETA=0

                                      Intercept
                        Intercept        and
          Criterion       Only       Covariates    Chi-Square for Covariates

          AIC              76.786        58.402         .
          SC               78.775        66.358         .
          -2 LOG L         74.786        50.402       24.384 with 3 DF (p=0.0001)
          Score              .             .          20.383 with 3 DF (p=0.0001)


                      Residual Chi-Square = 7.9652 with 5 DF (p=0.1582)



Step  4. Variable X1 entered:


             Model Fitting Information and Testing Global Null Hypothesis BETA=0

                                      Intercept
                        Intercept        and
          Criterion       Only       Covariates    Chi-Square for Covariates

          AIC              76.786        56.224         .
          SC               78.775        66.169         .
          -2 LOG L         74.786        46.224       28.561 with 4 DF (p=0.0001)
          Score              .             .          23.156 with 4 DF (p=0.0001)


                      Residual Chi-Square = 3.9490 with 4 DF (p=0.4129)


                                       The SAS System        21:18 Tuesday, April 2, 2002  19

                                   The LOGISTIC Procedure

NOTE: No (additional) variables met the 0.1 significance level for entry into the model.


                                Summary of Stepwise Procedure

                    Variable          Number       Score         Wald          Pr >
      Step    Entered     Removed         In    Chi-Square    Chi-Square    Chi-Square

         1    X6                           1       10.1174             .        0.0015
         2    X5                           2        7.8749             .        0.0050
         3    X8                           3        4.9956             .        0.0254
         4    X1                           4        4.1371             .        0.0420


                          Analysis of Maximum Likelihood Estimates

                  Parameter   Standard      Wald         Pr >      Standardized       Odds
  Variable   DF    Estimate     Error    Chi-Square   Chi-Square     Estimate        Ratio

  INTERCPT   1      -4.7050     1.5433       9.2950       0.0023              .       .
  X1         1       0.9239     0.4766       3.7583       0.0525       0.400918      2.519
  X5         1       1.4959     0.7439       4.0440       0.0443       0.405840      4.464
  X6         1       3.1355     1.2489       6.3031       0.0121       0.702768     23.000
  X8         1       1.9471     0.8466       5.2893       0.0215       0.523258      7.008


                Association of Predicted Probabilities and Observed Responses

                          Concordant = 87.1%          Somers' D = 0.766
                          Discordant = 10.4%          Gamma     = 0.786
                          Tied       =  2.5%          Tau-a     = 0.390
                          (728 pairs)                 c         = 0.883