To adjust for changes in the 2012 NIS design, AHRQ developed new 1993-2011 NIS Trend Weights for analysis spanning 2012 and earlier NIS data. The new NIS Trend Weights replace the earlier 1988-1997 NIS Trend Weights, which adjusted for changes following the 1998 NIS redesign.

The 1993-2002 Nationwide Inpatient Sample (NIS) Supplemental Discharge-Level Files facilitate analysis using multiple years of NIS data. The 1993-2002 NIS Supplemental Discharge-Level Files provide additional data elements that were added for later data years of the NIS through 2002 as well as updated Trend Weights.

• New Trend Weights for 1993-2011 HCUP NIS Data



• 1993-2002 NIS Supplemental Discharge-Level Files