The source reports same-day stays as zero days so the supplied length of stay was used to assign LOS when length of stay could not be calculated from dates.

Beginning with 2005, reported length of stay is no longer supplied.

LOS and LOS_X are artificially assigned to 0 on all records. California did not provide an admission date, discharge date, or length of stay. During HCUP processing, service date was loaded into the admission date (ADATE) and discharge date (DDATE) so that other variables like age at admission and discharge quarter could be calculated.

Length of stay was not provided on the source file. However, it was computed based on admission date (ADATE) and discharge date (DDATE) during the HCUP processing.

Starting in 2017, Hawaii supplies reported length of stay.

Prior to 2017, only the calculated length of stay could be used to assign LOS because Hawaii did not supply reported length of stay.

Only the calculated length of stay could be used to assign LOS because Indiana codes same day stays with a value of 1.

The reported length of stay was not used when LOS could not be calculated because Kansas coded same-day stays with a value of 1.

Only the calculated length of stay could be used to assign LOS because Maine did not supply reported length of stay.

Prior to July 2001, Maryland did not supply length of stay and reported only the date of service. LOS and LOS_X were therefore set to zero. Beginning in July 2001, Maryland provided the "From Date" and "To Date" resulting in calculation of the length of stay.

Beginning in 2006, LOS was calculated during the HCUP data processing.

Only the calculated length of stay was used because Massachusetts provided the total number of hours for the stay.

Beginning with the 2007 data, Missouri supplied admission and discharge dates for calculating LOS for all discharges. The reported length of stay was only used to assign LOS when dates were unavailable. Prior to 2007, the reported length of stay was not used when LOS could not be calculated because Kentucky coded same-day stays with a value of 1. The appropriate edit check for consistency of reported and calculated length of stay could not be performed.

The reported length of stay was not used when LOS could not be calculated because Nebraska coded same-day stays with the value 1.

Beginning with the 2005 New York identifies AIDS/HIV records by ICD-9-CM diagnosis code or 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 or 700 through 716.

Beginning with the 2007 data, North Carolina supplied admission and discharge dates for calculating LOS for almost all discharges. The reported length of stay was only used to assign LOS when dates were unavailable. Prior to 2007, the reported length of stay was not used when LOS could not be calculated because North Carolina coded same-day stays with a value of 1.

The reported length of stay was not used when LOS could not be calculated because South Carolina coded same-day stays with a value of 1.

The calculated length of stay was used to assign LOS because Utah did not report the length of stay. If either the discharge date or admission date was missing on the source record, then LOS is missing (.).

The reported length of stay was not used when LOS could not be calculated because Vermont coded same-day stays with the value 1.

Prior to 2007, Wisconsin does not supply length of stay. Length of stay is calculated from admission and discharge dates.

Beginning in 2007, we used the supplied length of stay to assign LOS and LOS_X when these fields could not be calculated from dates.