Disease Data variable selection runs

Full model (age, SES1,2, Sector)
MTB > blogist c15 = c11 c12 c13 c14
Binary Logistic Regression
Link Function:  Logit

Response Information
Variable  Value       Count
C15       1              31  (Event)
          0              67
          Total          98

Logistic Regression Table
                                                   Odds        95% CI
Predictor       Coef      StDev        Z     P    Ratio    Lower    Upper
Constant     -2.3129     0.6426    -3.60 0.000
C11          0.02975    0.01350     2.20 0.028     1.03     1.00     1.06
C12           0.4088     0.5990     0.68 0.495     1.50     0.47     4.87
C13          -0.3053     0.6041    -0.51 0.613     0.74     0.23     2.41
C14           1.5747     0.5016     3.14 0.002     4.83     1.81    12.91

Log-Likelihood = -50.527
Test that all slopes are zero: G = 21.263, DF = 4, P-Value = 0.000
----------------------------------
use only age
Entering data from file: F:\Drr99\ed257\web\exs\disease.DAT
     98 rows read.
MTB > blogistic c6 = c2
Binary Logistic Regression
Link Function:  Logit

Response Information
Variable  Value       Count
C6        1              31  (Event)
          0              67
          Total          98

Logistic Regression Table
                                                   Odds        95% CI
Predictor       Coef      StDev        Z     P    Ratio    Lower    Upper
Constant     -1.6244     0.4058    -4.00 0.000
C2           0.03183    0.01204     2.64 0.008     1.03     1.01     1.06

Log-Likelihood = -57.456
Test that all slopes are zero: G = 7.405, DF = 1, P-Value = 0.007

----------------------------------------------------
use all but age NWK p.588-9
MTB > blogistic c6 = c3 c4 c5
Binary Logistic Regression
Link Function:  Logit

Response Information
Variable  Value       Count
C6        1              31  (Event)
          0              67
          Total          98

Logistic Regression Table
                                                   Odds        95% CI
Predictor       Coef      StDev        Z     P    Ratio    Lower    Upper
Constant     -1.4392     0.4690    -3.07 0.002
C3            0.2351     0.5752     0.41 0.683     1.27     0.41     3.91
C4           -0.4779     0.5829    -0.82 0.412     0.62     0.20     1.94
C5            1.6203     0.4857     3.34 0.001     5.05     1.95    13.10

Log-Likelihood = -53.102
Test that all slopes are zero: G = 16.114, DF = 3, P-Value = 0.001
------------------------------------------
full model with SES dropped NWK p.589
MTB > blogist c6 = c2 c5
Binary Logistic Regression
Link Function:  Logit

Response Information
Variable  Value       Count
C6        1              31  (Event)
          0              67
          Total          98

Logistic Regression Table
                                                   Odds        95% CI
Predictor       Coef      StDev        Z     P    Ratio    Lower    Upper
Constant     -2.3352     0.5111    -4.57 0.000
C2           0.02929    0.01317     2.22 0.026     1.03     1.00     1.06
C5            1.6735     0.4873     3.43 0.001     5.33     2.05    13.85

Log-Likelihood = -51.130
Test that all slopes are zero: G = 20.058, DF = 2, P-Value = 0.000