National Hospital Discharge Survey (NHDS) Restricted Data, 1965-2010

The National Hospital Discharge Survey (NHDS), conducted from 1965 to 2010, was 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. 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).