Central Distributor SID: Description of Data Elements

DOB - Date of birth

Documentation Sections:

General Notes

Uniform Values

State Specific Notes

General Notes

DOB is assigned a valid nonmissing birthdate, with the following exceptions: If a date of birth is supplied by the data source, but one or more of the components of the birthdate (year, month, day) is Blank or a documented missing value, then DOB = missing (.). - or - Nonnumeric or out of range (year NE 00-99, month NE 1-12, day NE 1-31), then DOB = invalid (.A). If the day of birth is inconsistent with the month (e.g., February 30), then DOB = invalid (.A). If the data source does not provide the date of birth, then beginning in the 1998 data, DOB is not present on the HCUP files. In the 1988-1997 data, DOB is retained on the HCUP files and is set to unavailable from source (.B). If the birthdate is confirmed to be a valid date, but the calculated age is negative: Beginning in the 1998 data, DOB and AGE are set to inconsistent (.C) by edit check EAGE02. AGEDAY and AGEMONTH are set to missing (.). From 1988-1997 data, DOB remains unchanged, and AGE and AGEDAY are set to invalid (.A). AGEMONTH is not available on the 1988-1997 HCUP databases. To ensure the confidentiality of patients on the HCUP Central Distributor files, full dates are not released. Beginning in the 1998 data, DOB is replaced by birth month (BMONTH) and birth year (BYEAR). In databases before 1998, the day portion of the date stored in DOB 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 DOB are computed before DOB is masked.

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Uniform Values

Variable Description Value Value Description DOB Date of birth YYYYMMDD Date of Birth . Missing .A Invalid .B Unavailable from source (coded in 1988-1997 data only) .C Inconsistent: beginning with 1998 data, EAGE02

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State Specific Notes

Arizona The coding of date of birth (DOB) and the use of the reported age differs across years: Starting in 1996 Arizona reported a four-digit year for date of birth (DOB). If the reported four-digit birth year was greater than the admission year then the original date of birth remains unchanged and the age at admission (AGE and AGEDAY) was set to inconsistent (C.) beginning in 1998 and invalid (A.) in 1996-1997. The reported age was not used because it is the age at the time of discharge. 1995 Arizona reported a two-digit year for date of birth (DOB). During HCUP processing, the birth century was assigned as 1800 if the reported age was at least 100 or the reported date of birth was after the admission date. Birth century was assigned as 1900 for all other records. Prior to 1995 Arizona reported a four-digit year for date of birth(DOB). If the reported four-digit birth year was greater than the admission year, the reported age was checked. If the reported age was greater than the two-digit discharge, DOB is imputed as a date in 1800, instead of 1900. For example, if a 1993 discharge had a reported date of birth of January 1, 1999 and a reported age of 94, then DOB was set to January 1, 1899. Due to an error during HCUP processing of 1990 and 1991 discharges, some birthdates were converted to incorrect SAS missing values. DOB should have retained the erroneous date, however, DOB was set to .B or .C by mistake. DOB Value 1990 Count 1991 Count January 3, 1999 .B 2 2 January 4, 1999 .C 1 0 DOB was processed correctly for discharges in years other than 1990 and 1991.

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