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Central Distributor SASD: Description of Data Elements

DDATE - Discharge date
Documentation Sections:
General Notes
Uniform Values
State Specific Notes
General Notes

Discharge date (DDATE) is assigned a valid nonmissing date, with the following exceptions:

  • If a discharge date is supplied by the data source, but one or more of the components of the discharge date (year, month, day) is
    • Blank or a documented missing value, then DDATE = missing (.).
    • - or -
    • Nonnumeric or out of range (year NE 00-99, month NE 1-12, day NE 1-31), DDATE = invalid (.A).
  • If the discharge day is inconsistent with the month (e.g., February 30), then DDATE = invalid (.A).
  • If the data source does not provide the discharge date, then beginning in the 1998 data, DDATE is not present on the HCUP files. In the 1988-1997 data, DDATE is retained on the HCUP files and is set to unavailable from source (.B).

To ensure the confidentiality of patients on the HCUP Central Distributor files, full dates are not released. Beginning in the 1998 data, DDATE is replaced by discharge month (DMONTH) and discharge year (YEAR). In databases before 1998, the day portion of the date stored in DDATE is overwritten with "01" during the creation of the Distributor files. The month and year portion of the date remains unchanged. HCUP data elements that are calculated from DDATE are computed before DDATE is masked.

Uniform Values
VariableDescriptionValueValue Description
DDATEDischarge dateYYMMDDDate of Discharge
.BUnavailable from source (coded in 1988-1997 data only)
State Specific Notes


Beginning in 1997, Colorado provided the discharge date (DDATE) with a four-digit year. In prior years, only a two-digit year was available.

New York

Beginning with the 2008 data,the HCUP data element DDATE is missing (.) for AIDS/HIV patients. New York identifies AIDS/HIV records by ICD-9-CM diagnosis code, DRG, or MS-DRG:

  • An admitting, principal or any secondary diagnosis of "042", "043", "044", "7958", "27910", "27919", "2793", "1363", "79571", "07951", "07952", "07953", "V017" or "V08".
  • A DRG of 488 through 490 (prior to October 2007) or MS-DRG of 700 through 716 (beginning in October 2007).

Please note that the admitting diagnosis is not retained in the HCUP databases prior to 2012.

From 2002 - 2004, both ADATE and DDATE were loaded from the admission date because full admission dates were provided, but only the year and month was provided for the services/discharge date.


Internet Citation: HCUP Central Distributor SASD Description of Data Elements - All States. Healthcare Cost and Utilization Project (HCUP). May 2024. Agency for Healthcare Research and Quality, Rockville, MD.
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Last modified 5/22/24