10.3886/ICPSR04166.v1 United States Department of Health and Human Services. National Center for Health Statistics Inter-university Consortium for Political and Social Research 2004 health care facilities hospitalization hospitals illness medical care medical evaluation medical procedures medical records patients payment methods treatment 2004-12-21 2005-11-04 administrative records data 4166 1 The National Hospital Discharge Survey (NHDS) collects medical and demographic information annually from a sample of hospital discharge records. Variables include patients' demographic characteristics (sex, age, race, marital status), dates of admission and discharge, source and type of admission, status at discharge, final diagnoses, surgical and nonsurgical procedures, dates of surgeries, and sources of payment. Information on hospital characteristics such as bedsize, ownership, and region of the country is also included. The medical information is coded using the INTERNATIONAL CLASSIFICATION OF DISEASES, 9TH REVISION, CLINICAL MODIFICATION (ICD-9-CM).