User Support

Do Your own analysis
Explore Expert Research & Limited Datasets

KID Description of Data Elements

KID_STRATUM - Stratum used to post-stratify hospital
Documentation Sections:
General Notes
Uniform Values
State Specific Notes
General Notes

KID_STRATUM is a four-digit stratum identifier used to post-stratify hospitals for the calculation of universe weights.

The hospital's census region, control category, location, teaching status, and bedsize were obtained from the AHA Annual Survey of Hospitals.

  • A metropolitan statistical area is considered urban, and a non-metro statistical area is rural.
  • Teaching hospitals have an AMA-approved residency program or have membership in the Council of Teaching Hospitals.
  • Bedsize assesses the number of short-term acute beds in a hospital.

The hospital's bedsize category is nested within location and teaching status.

Location and Teaching Status Bedsize
Small Medium Large
Rural 1-49 50-99 100+
Urban, nonteaching 1-99 100-199 200+
Urban, teaching 1-299 300-499 500+

Some strata were combined for sampling and weight calculations. Consequently, a given hospital's actual value for a stratifier may differ from those indicated by the value of KID_STRATUM. Each hospital's actual values of stratifiers are contained in separate variables:

Stratifier Variable
Ownership/Control H_CONTRL
Location/Teaching H_LOCTCH
Bedsize H_BEDSZ

Collapse KID_STRATUM for Small Cell Size. If fewer than two frame hospitals, less than 30 uncomplicated births, less than 30 complicated births, and less than 30 non-birth pediatric discharges were contained in a stratum, then the second digit (control) was set to 2 (Private).

Children's Hospitals. KID_STRATUM was set to 9999 (or 9998 in the 2003 KID) for children's hospitals. The AHA Annual Survey of Hospitals and information from the National Association of Children's Hospitals and Related Institutions (NACHRI) were used to identify children's hospitals. AHRQ was consulted about the resolution of any inconsistencies in the coding of hospital type.

Uniform Values
VariableDescriptionValueValue Description
KID_STRATUMStratum used to post-stratify hospitalnnnn1st Digit = 1 Geographic: Northeast (1), Midwest (2), South (3), West (4)
2nd Digit = 2 Control: Government, nonfederal (1), Private, not-for-profit (2), Private, investor-owned (3), Private, either not-for-profit or investor-owned (4)
3rd Digit = 3 Location / Teaching: Rural (1), Urban nonteaching (2), Urban teaching (3)
4th Digit = 4 Bedsize: Small (1), Medium (2), Large (3)
9999 or 9998Children's Hospital
State Specific Notes

Internet Citation: HCUP KID Description of Data Elements. Healthcare Cost and Utilization Project (HCUP). September 2008. Agency for Healthcare Research and Quality, Rockville, MD.
Are you having problems viewing or printing pages on this website?
If you have comments, suggestions, and/or questions, please contact
Privacy Notice, Viewers & Players
Last modified 9/17/08