At A Glance
Noteworthy Characteristics
- Provides information on hospital stays related to obesity conditions.
- Includes data on children’s diagnoses for food- and obesity-related conditions.
Website
http://www.cdc.gov/nchs/nhds.htm
Purpose
To collect data about demographics and medical diagnoses and treatments for patients discharged from hospitals in the United States (U.S.).
Target Population
Patients discharged from non-federal, short-term hospitals in the U.S.
Conducted
Began in 1965 and ended after the 2010 data collection year. Has been replaced with the National Hospital Care Survey. For more information on this survey go to http://www.cdc.gov/nchs/nhcs.htm.
Sponsor
National Center for Health Statistics, Centers for Disease Control and Prevention, U.S. Department of Health and Human Services
Special Note(s)
The survey was redesigned in 1988. Another survey redesign began in 2010.
The unit of analysis is the discharge event rather than the patient, so an individual who experienced more than one hospital stay and discharge during the year could be selected more than once for inclusion in NHDS. For this reason, this survey is not useful for providing prevalence estimates. Federal, military, Department of Veterans Affairs, and institutional hospitals (e.g., prisons) are excluded.
See also National Hospital Ambulatory Medical Care Survey (NHAMCS) and the National Ambulatory Medical Care Survey (NAMCS) for data on patients and treatment in outpatient departments, emergency rooms, ambulatory surgery locations, and in doctors’ offices.
Sampling
Sample Design
Cross-sectional survey.
Three-stage national probability stratified design. Learn more about the sampling design.
Sample Size
Approximately 203 hospitals in 2010. Approximately 152,000 in-patient discharges (unit of analysis) in 2010.
Special Note(s)
Through 2007, the sample included about 500 short-stay, non-federal hospitals. The sponsor reduced the sample size by approximately 50 percent for the 2008 through 2010 data collection periods.
Hospitals were selected from a frame of short-stay hospitals. Some hospitals and geographical areas were selected with certainty, and the remaining hospitals were selected using a three-stage stratified design with National Health Interview Survey (NHIS) primary sampling units (PSUs) at the first stage.
As a nationally representative sample survey, the National Hospital Discharge Survey is most likely to yield reliable annual estimates for the types of hospitalizations and procedures that are relatively common. Estimates for those not often hospitalized (e.g., children), particularly those with uncommon conditions and treatments, may not be reliable if only 1 year of data are used in an analysis. For some conditions, combining data over multiple years will yield reliable data. Data beginning in 2008, when the NHDS sample was halved, is even less likely to be reliable using only 1 year of data, especially for children.
Key Variables
Demographic
| Name | Methods of Assessment |
|---|---|
| Patient age | Hospital medical records |
| Patient date of birth (restricted) | Hospital medical records |
| Patient race/ethnicity | Hospital medical records |
| Patient sex | Hospital medical records |
| Payer source | Hospital medical records |
Geocode/Linkage
| Name | Methods of Assessment |
|---|---|
| Hospital zip code (restricted) | Interview/questionnnare |
| Patient residential zip code (restricted) | Hospital medical records |
Other
| Name | Methods of Assessment |
|---|---|
| Diagnoses | Hospital medical records |
| Patient status at discharge | Hospital medical records |
| Procedures done during hospitalization | Hospital medical records |
Data Access and Cost
Data Availability
Download data.
Data also are available on CD-ROM. Contact the Hospital Care Team at nhds@cdc.gov to get copies of the 1970-1978 and the 1979-2007 multiyear CD-ROMs. Individual year data files, including those for 2008, 2009 and 2010, can be downloaded from the link above.
Cost
Free of charge. Restricted data are fee-based. Set-up fee is $750 per day. Learn more about additional fees.
Special Note(s)
Information on date of birth and patient’s residential zip code are not available in the public-use dataset. These variables can be used for research pending approval by the National Center for Health Statistics Research Data Center.
Beginning in April 2003, medical record numbers were no longer captured on data collection forms to comply with the April 14, 2003, Privacy Rule of the Health Insurance Portability Accountability Act (HIPAA).
Geocode/Linkage
Geocode Variable(s)
Hospital zip code (restricted); patient residential zip code (restricted)
Existing Linkages
The National Center for Health Statistics (NCHS) can link estimates from NHDS data to other data, including county data from the Health Resources and Services Administration’s Area Resource File and zip code level data from the U.S. Census Bureau. Both of these sources provide data on socioeconomic characteristics of these geographical areas.
NHDS Pollution Exposure data files are linked to NHDS through the NCHS Research Data Center. These data are linked using zip code of residence and admission date and are used to examine associations between air quality and hospitalizations in the U.S.
Selected Publications
General
National Center for Health Statistics. 2007 National Hospital Discharge Survey: Summary National Health Statistics Reports. Hyattsville (MD): National Center for Health Statistics, 2010. Report No. 29.
Weight-Related
Koebnick C, Getahun D, Reynolds K, Coleman KJ, Porter AH, Lawrence JM, Punyanitya M, Quinn VP, Jacobsen SJ. Trends in nonalcoholic fatty liver disease-related hospitalizations in U.S. children, adolescents, and young adults. Journal of Pediatric Gastroenterology and Nutrition 2009;48(5):597-603.
Wang G, Dietz WH. Economic burden of obesity in youths aged 6 to 17 years: 1979-1999. Pediatrics 2002;109(5):E81-1.
Resources
Documentation/Codebook(s)
ftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Dataset_Documentation/NHDS/">ftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Dataset_Documentation/NHDS/
General
Data in table form is available here.
