Disease Staging was assigned using software developed by Medstat. Starting with the 2008 NIS, this data element is unavailable because it was discontinued as part of the Disease Staging software. This severity measure includes the disease category and stage for the principal diagnosis and predictive scales for mortality, length of stay, and total charges. The prefix "DS_" has been included in the data element name to distinguish the Disease Staging measures from other HCUP data elements. For more information, please refer to the following documents available on the NIS Documentation CD-ROM and on the HCUP User Support Website (www.hcup-us.ahrq.gov):

• Overview of Severity Systems
• Disease Staging V5.2 Diagnostic Categories
• Disease Staging V5.2 Reference Guide

For the 2003 KID, this data element is not available for discharges from Pennsylvania.