The ID statement specifies variables that identify observations in plots and in output data sets, but the ID variable doesn't change the analysis.
From what little information you've provided, I suggest you look at the "Analysis of Clustered Data" example in the PHREG documentation, which uses a RANDOM statement. The doc for the RANDOM statement explains the statistical details of the model that is fit when you use the RANDOM statement.
Registration is open! SAS is returning to Vegas for an AI and analytics experience like no other! Whether you're an executive, manager, end user or SAS partner, SAS Innovate is designed for everyone on your team. Register for just $495 by 12/31/2023.
If you are interested in speaking, there is still time to submit a session idea. More details are posted on the website.