Logistic Regression Options

You can specify options for your logistic regression analysis:

Statistics and Plots. Allows you to request statistics and plots. Available options are Classification plots, Hosmer-Lemeshow goodness-of-fit, Casewise listing of residuals, Correlations of estimates, Iteration history, and CI for exp(B). Select one of the alternatives in the Display group to display statistics and plots either At each step or, only for the final model, At last step.

  • Hosmer-Lemeshow goodness-of-fit statistic. This goodness-of-fit statistic is more robust than the traditional goodness-of-fit statistic used in logistic regression, particularly for models with continuous covariates and studies with small sample sizes. It is based on grouping cases into deciles of risk and comparing the observed probability with the expected probability within each decile.

Probability for Stepwise. Allows you to control the criteria by which variables are entered into and removed from the equation. You can specify criteria for Entry or Removal of variables.

  • Probability for Stepwise. A variable is entered into the model if the probability of its score statistic is less than the Entry value and is removed if the probability is greater than the Removal value. To override the default settings, enter positive values for Entry and Removal. Entry must be less than Removal.

Classification cutoff. Allows you to determine the cut point for classifying cases. Cases with predicted values that exceed the classification cutoff are classified as positive, while those with predicted values smaller than the cutoff are classified as negative. To change the default, enter a value between 0.01 and 0.99.

Maximum Iterations. Allows you to change the maximum number of times that the model iterates before terminating.

Include constant in model. Allows you to indicate whether the model should include a constant term. If disabled, the constant term will equal 0.

Specifying Logistic Regression Options

This feature requires Custom Tables and Advanced Statistics.

  1. From the menus choose:

    Analyze > Regression > Binary Logistic…

  2. In the Logistic Regression dialog box, click Options.