Age in years (AGE) is calculated from the birth date (DOB) and the admission date (ADATE) in the HCUP State databases with the few exceptions listed below. Ages over 89 are aggregated into a single category of 90 years or older in the HCUP nationwide databases starting in data year 2012.

Exceptions for assigning AGE:

• AGE is set to the supplied age if the age cannot be calculated (ADATE and/or DOB is missing or invalid). Note: If the supplied age is the age at discharge instead of the age at admission, then the supplied age is NOT used.
• AGE is missing (.) if the age cannot be calculated and the supplied age is missing.
• AGE is invalid (.A) if
  • it is out of range (AGE NE 0-124) or
  • the age cannot be calculated and the supplied age is nonnumeric.

  An invalid calculated AGE is not replaced by the supplied age.

• If the data source does not provide the necessary dates to calculate age or the reported age at admission, then beginning in the 1998 data, AGE is not present on the HCUP files. In the 1988-1997 data, AGE is retained on the HCUP files and is set to unavailable from source (.B).
• AGE is set to inconsistent (.C) if one of the HCUP edit checks is triggered. The age edit checks vary by year.
  • Beginning in the 1998 data, AGE is less than 0 (EAGE02), is greater than 124 (EAGE03), is inconsistent with neonatal diagnoses (EAGE04), or is inconsistent with maternal diagnoses/procedures (EAGE05).
  • From 2006-2014, AGE is inconsistent with the HCPCS procedure codes (ECPT03)
    • We discontinued age edits for HCPCS level I (CPT codes) beginning with data year 2011 and we discontinued age edits for all other HCPCS codes beginning in 2015.
  • In the 1988-1997 data, AGE is inconsistent with AGEDAY (ED021), neonatal diagnoses (ED3nn), maternal diagnoses (ED4nn), or maternal procedures (ED5nn).

When processing the 1996 HCUP data, no adjustment was made for the leap year when age was calculated from date of birth and admission date. This caused infants admitted on the day before their first birthday to have AGE=1 instead of AGE.

The reported age was not used when AGE could not be calculated because Arizona supplied age at discharge.

Beginning with 2005, source AGE is no longer supplied.

In all years, California assigned the date of birth to admission date when the admission date was not reported and the discharge had a principal diagnosis indicating a newborn (defined as DX1 equal to V3x.0x). This caused the calculated age to be 0 days.

Prior to 1995, California reported ages at discharge. Only the calculated age was used to assign AGE.

Beginning in 1995, California reported ages at admission. When AGE could not be calculated from dates, the reported age was assigned.

Patient age could not be calculated from dates since Connecticut did not report full dates of birth. During HCUP processing, only the reported age could be used to assign AGE.

Beginning in 2004, Florida provides DOB and ADATE for all discharges.

In 1997, patient age could not be calculated from dates since Florida did not report admission or birth dates. During HCUP processing, the reported age was used to assign AGE. From 1998 to 2001, Florida supplied admission date and date of birth for patients less than 11 years old. For patients over 10 years old, the reported age in years was used to assign AGE. Beginning in 2002, Florida reported age for all discharges, but did not provide admission date and date of birth.

Beginning in 2017, Hawaii does not provide date of birth (DOB).

Beginning in 1998, Hawaii provided the date of birth (DOB) with a four-digit year.

In prior years, only a two-digit year was available. To compensate for the two-digit birth year, the birth century was assigned as 1800 if the reported date of birth was after the admission date. Birth century was assigned as 1900 for all other records.

Only the calculated age could be used to assign AGE because Illinois did not supply age in years.

AGE may differ by one year from the actual age. When only the year of birth is available, Iowa assigns the day and month of birth to '01', which may cause the age calculated from birth date to be one year less than the actual age.

Starting with Version 3 of the 2012 SASD and SEDD (created in 2017), the patient age (AGE) is set to 90 for patients age 90 years and older.

Beginning in 2013, the supplied age in years is used when the data element cannot be calculated.

Prior to October 1998, ages greater than 100 years should be interpreted with caution. Age is calculated using the birth and admission date, but only a two-digit year for date of birth (DOB) was provided by the data source. An additional indicator variable provided by the data source, the "Century Birth date," indicates whether the age of the patient was greater or less than 100 years. HCUP experience has shown that this indicator was often not set when it should have been. Thus, if the century indicator specified 1800 or the birth date occurred after the admit date, the century for the date of birth was set to 1800. If the birth date is erroneously after the admit date, this rule causes the age in years (AGE) to be incorrectly greater than 100. If the age does not agree with neonatal or maternal diagnoses and/or procedures, the age is set to inconsistent (.C).

Beginning in October 1998, Massachusetts provides a four-digit birth year. The birth century indicator and the admission date are not used to modify the date of birth.

For discharges less than 90 years old, if the age could not be calculated from dates, then the reported age was used to assign AGE. For discharges that are 90 or older, only the calculated age could be used to assign AGE because Nevada sets age in years to 90 for all discharges age 90 and above.

Beginning in 2009 AGE was provided. In 2008, Age was calculated during the HCUP processing.

Prior to 1994, New Jersey reports age as a two-digit code with a maximum of 99 and provides a birth century indicator. Beginning in 1994, New Jersey provides a four-digit birth year. If age could not be calculated (ADATE or DOB missing or invalid) then age was assigned as follows:

Beginning with the 2008 data, the HCUP data element AGE 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.

In the 1988-1997 HCUP New York databases, AGE could not be calculated because New York did not report full admission and birth dates. During HCUP processing, only the reported age in years could be used to assign AGE.

Beginning with the 2008 data, the HCUP data element AGE 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.

In the 1988-1997 HCUP New York databases, AGE could not be calculated because New York did not report full admission and birth dates. During HCUP processing, only the reported age in years could be used to assign AGE.

The calculation of AGE differs across years.

Beginning in 2000

South Carolina reported a four-digit year for date of birth (DOB). No adjustments to birth century were made during HCUP processing.

From 1996 to 1999

Only a two-digit year for date (DOB) was provided by the data source.

• If DOB > admission date (ADATE), the birth century was assigned as 18 (e.g., if ADATE = 01/02/88 and DOB = 01/03/88, then the birth year was set to 1888 and the calculated age was 99).
• If DOB <= ADATE, the birth century was assigned as 19 (e.g., if ADATE = 01/02/88 and DOB = 01/01/88, then the birth year was set to 1988 and the calculated age in years was 0).

Using only the admission date to determine births in the 1800s causes no patient ages to be greater than 99 years.

In 1993 and 1995

South Carolina 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.

In 1994

South Carolina reported a four-digit year for date of birth (DOB). No adjustments to birth century were made during HCUP processing.

Prior to 2008, only the calculated age could be used to assign AGE because Tennessee did not supply age in years.

Prior to 2004, the reported age was not used when AGE could not be calculated because Utah supplied age at discharge. Beginning in 2004, Utah supplied the age at admission which was used during HCUP processing.

Beginning with the 2015 data, the HCUP data element AGE is set to missing (.) in the Central Distributor SID for records involving substance abuse or HIV infection. This was done at the request of the Utah Partner organization.

Beginning in 2005, Wisconsin no longer codes ages greater than 96 to 96. Prior to 2005, an error during HCUP processing of 1989-1992 discharges caused age in years (AGE) and date of birth (DOB) to be set to missing (.) for all patients born in the year 1900. Beginning with 1993 discharges, AGE and DOB were processed correctly.

From 1989-1994, only the calculated age could be used to assign AGE because Wisconsin did not supply age in years. The appropriate edit check for consistency of reported and calculated ages could not be performed.

For 1995 discharges, the source supplied an age in years which was used if the age could not be calculated from date of birth and admission date.

Beginning in 1996, only the calculated age could be used to assign AGE because Wisconsin had truncated ages over 96 years to age 96.

Beginning in 2005, Wisconsin no longer codes ages greater than 96 to 96. Prior to 2005, only the calculated age could be used to assign AGE because Wisconsin groups ages greater than 96. AGE was calculated using the date of birth and date of principal procedure because the admission date is not provide by the state.