Distribution

This option can be different for different reports.

For Intervention and Disposition reports:

Check this option to include a distribution for either Interventions or Disposition data.

To Specify This Option:

8 Click within the check box.

For Adverse Events Time to Event:

Use this option to choose the distribution the event counts are assumed to follow.

Negative binomial fits an extra parameter k that can account for over-dispersion.

Note: This option is available only when the Response Type is an incidence density.

To Specify the Distribution:

8 Make sure that either Incidence density based on first event only or Incidence density based on all events is specified as the Response Type.
8 Click within the radio button for the desired distribution.

Note: If s you see errors regarding NEWRAP convergence in the SAS log after you run an ANOVA report with Negative Binomial selected, you should consider either switching to a Poisson distribution or increasing the value specified in the Gradient Convergence Criterion. This will effectively reduce the restrictive criterion and help you avoid this convergence error.