Trend Weights for HCUP NIS Data
Previous Trend Weights for 1988-1997 HCUP NIS Data
Trend Weights for 1993-2011 HCUP NIS Data
The NIS is available yearly, beginning with 1988, allowing analysis of trends over time. Analyses of time trends using the HCUP NIS are recommended from 1993 forward.
As a result of the changes implemented in the redesign, users should expect one-time disruptions to historical trends for counts, rates, and means estimated from the NIS, beginning with data year 2012. For 2012 we expect overall trends in discharge counts to decline by about 4.3 percent, overall trends in average length-of-stay to decline by about 1.5 percent, overall trends in total charges to decline by about 0.5 percent, and overall trends in hospital mortality to decline by about 2.0 percent. For a detailed description of the effects of the design changes on sample estimates, please see the NIS Redesign Report available on the HCUP User Support (HCUP-US) Website.
In order to facilitate analysis of trends using multiple years of NIS data, AHRQ developed new discharge trend weights for the 1993-2011 NIS. These weights were calculated in the same way as the weights for the redesigned 2012 NIS, and are designed to be used instead of the original NIS discharge weights for trends analysis. For trends analysis using NIS data 2011 and earlier, revised weights should be used to make estimates comparable to the new design beginning with 2012 data. The new trend weights replace the earlier NIS Trend Weights and NIS Trends Supplemental Files that were developed for the 1988-1997 NIS following the 1998 NIS redesign. The report Using the HCUP Nationwide Inpatient Sample to Estimate Trends1, available on the HCUP-US Website under Methods Series, includes recommendations for trends analysis.
1 As of June, 2014, this report had not yet been updated for the new 2012 NIS design. However, the methods described in the report are still valid.
The trend weights are available for download as ASCII files along with SAS, Stata, and SPSS load programs. Each file contains the following three data elements:
* The 2000 file contains a second trend weight: TRENDWTcharge. For 2000, use TRENDWT to create national estimates for all analyses except those that involve total charges; and use TRENDWTcharge to create national estimates of total charges. For all other years, use TRENDWT for all estimates.
NIS Trend Weights files for download:
|Internet Citation: HCUP NIS Trend Weights. Healthcare Cost and Utilization Project (HCUP). June 2014. Agency for Healthcare Research and Quality, Rockville, MD. www.hcup-us.ahrq.gov/db/nation/nis/trendwghts.jsp.|
|Are you having problems viewing or printing pages on this Website?|
|If you have comments, suggestions, and/or questions, please contact email@example.com.|
|Privacy Notice, Viewers & Players|
|Last modified 6/26/14|