Odds Ratio
The odds ratio is useful in the interpretation of the results of logistic
regression (see Neter, Wasserman, and Kutner, 1989) and is computed
from a 2x2 classification table, which displays the predicted and observed
classification of cases for a binary dependent variable:
(f11*f22)/(f12*f21)
where fij represents the
respective frequencies in the 2x2 table.
See Nonlinear
Estimation for more details.