About the Hospital Care Surveys

National Hospital Discharge Survey

The National Hospital Discharge Survey (NHDS), conducted from 1965 to 2010, is a national probability survey designed to meet the need for information on characteristics of inpatients discharged from non-Federal short-stay hospitals in the United States. From 1988-2007 the NHDS collected data from a sample of approximately 270,000 inpatient records acquired from a national sample of about 500 hospitals. From 2008 to 2010 the sample size was reduced to 239. Only hospitals with an average length of stay of fewer than 30 days for all patients, general hospitals, or children’s general hospitals are included in the survey. Federal, military, and Department of Veterans Affairs hospitals, as well as hospital units of institutions (such as prison hospitals), and hospitals with fewer than six beds staffed for patient use, are excluded.

Beginning in 1988, two data collection procedures have been used in the survey. One is a manual system in which sample selection and medical transcription from the hospital records to abstract forms is performed by the hospital’s staff or by staff of the U.S. Bureau of the Census on behalf of NCHS. The other data collection procedure is an automated system in which NCHS purchases electronic data files from commercial organizations, State data systems, hospitals, or hospital associations. The medical abstract form and the automated data tapes contain items that relate to the personal characteristics of the patient. These items include age, sex, race, ethnicity, marital status, and expected sources of payment. Administrative items such as admission and discharge dates (which allow calculation of length of stay), as well as discharge status are also included. Medical information about patients includes diagnoses and procedures coded to the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM).

A detailed description of the NHDS is included in "Design and Operation of the National Hospital Discharge Survey: 1988 Redesign," Vital and Health Statistics, Series 1, Number 39. PDF Version (1 MB)

Data from the NHDS are available annually from 1970 to 2009 and are used to examine important topics of interest in public health and for a variety of activities by governmental, scientific, academic, and commercial institutions. National Hospital Discharge Survey data are available in publications, CD-ROMs and downloadable files from the FTP server.

National Hospital Care Survey

The National Hospital Care Survey (NHCS) is a new survey started in 2011 that integrates inpatient data formerly collected by the NHDS with emergency department (ED), outpatient department (OPD), and ambulatory surgery center (ASC) data collected by the National Hospital Ambulatory Medical Care Survey. Currently a sample of 500 non-institutional, non-federal hospitals with six or more beds in the United States is being recruited for this survey. During the first two years of the survey, sampled hospitals will be asked to provide data Uniform Bill (UB)-04 administrative claim data for all inpatients, as well as facility-level data through a facility questionnaire. In 2013, in addition to inpatient data, the hospitals will be asked to provide data on the utilization of health care services provided in their EDs, OPDs, and ASCs. Also in 2013, a sample of freestanding ASCs will be recruited.

You can learn more about the survey at: /nchs/nhcs.htm.