I'm not sure how to interpret my binary logistic regression output from SPSS My dependant variable is diagnosis of cancer malignant being 0 and benign being 1.  And my covariate is mean radius (of the tumour).  I get this:  
Variables in the Equation: 

                     B       S.E.   Wald    df   Sig.   Exp(B)  95% C.I.for EXP(B)  
                                                                Lower   Upper
Step 1a radius    1.020      .104   96.518  1   .000    2.774   2.263   3.401
        Constant -15.039    1.474   104.091 1   .000    .000        

a Variable(s) entered on step 1: radius.            

How do I interpret this in words? 
 A: The interpretation of the output is given below:
B - This is the coefficient for the constant (also called the "intercept") in the model.
S.E. - This is the standard error around the coefficient for the constant
Wald and Sig. - 
This is the Wald chi-square test that tests the null hypothesis that the constant equals 0.  This hypothesis is rejected because the p-value (listed in the column called "Sig.") is smaller than the critical p-value of .05 (or .01).  Hence, we conclude that the constant is not 0.
df - This is the degrees of freedom for the Wald chi-square test.  There is only one degree of freedom because there is only one predictor in the model, namely the constant.
Exp(B) - This is the exponentiation of the B coefficient, which is an odds ratio.  This value is given by default because odds ratios can be easier to interpret than the coefficient, which is in log-odds units. 
95% C.I.for EXP(B): This is confidence interval (95%) for Exp(B), it can be anywhere between  2.263  and 3.401
Hope this helps !
