Case Mix Data Documentation Archive


Hospital Inpatient Discharge Database (HIDD) Documentation Manuals

The Hospital Inpatient Discharge Database (HIDD) documentation manuals consist of two sections: the General Documentation section and the Technical Documentation section.

The General Documentation section is intended to provide users with an understanding of the data quality issues connected with certain data elements and includes background on the database’s development and the DRG Groupers. The section also contains hospital-reported discrepancies received in response to the data verification process, supplements listing the hospitals within the database, information on mergers, name changes, closures, conversion, and non-acute care hospitals, and alphabetical and numerical payer source lists.

The Technical Documentation section includes information on the fields calculated by CHIA and a data file summary describing the hospital data that is contained in the file. The manuals also contain the Discharge File Table (formerly the record layout), Revenue File Table, Data Code Tables, and revenue code mappings.


Outpatient Observation Database (OOD) Documentation Manuals

The Outpatient Observation documentation manuals consist of two sections: the General Documentation section and the Technical Documentation section.

The General Documentation section includes background on the database’s development and is intended to provide users with an understanding of the data quality issues connected with certain data elements. This section also contains hospital reported discrepancies received in response to the data verification process, and supplementary information, including a table of data field names and descriptions, a list of Type A and Type B errors, and a list of hospitals within the database. The Technical Documentation section includes information on the fields calculated by CHIA and a data file summary section describing the data that is contained in the file.


Emergency Department (ED) Database Documentation Manuals

The Emergency Department documentation manuals contain two sections: the General Documentation section and the Technical Documentation section.

The General Documentation section includes background on the database’s development and is intended to provide users with an understanding of the data quality issues connected with certain data elements. The section also contains hospital-reported discrepancies received in response to the data verification process, and supplementary information, including a table of data field names and descriptions, a list of Type A and Type B errors, and a list of hospitals within the database. The Technical Documentation section includes information on the fields calculated by CHIA and a data file summary section describing the data that is contained in the file.

The following tables provide information on visit volume for all Emergency Departments regardless of discharge disposition across the state of Massachusetts. Outpatient visit totals were obtained through the Outpatient Emergency Department Database, while the Emergency Department visits that resulted in an inpatient admission or observation stay were identified through the Inpatient Discharge Database and Outpatient Observation Database, respectively. In both databases, Emergency Department flags were used to mark visits originating in the ED. The tables can be used to identify hospitals with high ED volume, as well as to indicate differences in disposition pattern.