This section provides State-specific information on the original data files provided by the HCUP Partner organizations for the development of the HCUP inpatient databases. Information includes the source of the original data files, the types of hospitals included in those files, the records excluded during HCUP processing (if any), and other pertinent information to understand the composition of these files. For a description of the file composition for one or multiple States, check the corresponding boxes below and then click the "View File Composition" button.

Overview of the SID

The SID are a set of all-payer inpatient databases from participating HCUP Partners that capture hospital inpatient stays in a given State. The SID include all or nearly all hospitalizations in participating States in a uniform format to facilitate multi-State comparisons and analyses. The SID contain a core set of clinical and nonclinical information on all patients, regardless of payer, including persons covered by Medicare, Medicaid, private insurance, and the uninsured.

Outpatient services, such as emergency department (ED) services or observation services (OS) can often occur in combination with an inpatient stay. Therefore, the SID may include records for inpatient stays that began in the ED or in observation. Inpatient records with evidence of ED services or OS can be identified using two separate HCUP variables — HCUP_ED and HCUP_OS. The availability of information on inpatient stays involving ED services or OS varies substantially across States and data years as it is dependent on the SID including the necessary underlying data, such as revenue center codes.

The SID are calendar year files for all data years except 2015. Because of the transition to ICD-10-CM/PCS on October 1, 2015, the 2015 SID are split into two parts. Nine months of the 2015 data with ICD-9-CM codes (discharges from January 1, 2015 - September 30, 2015) are in one set of files labeled Q1Q3. Three months of 2015 data with ICD-10-CM/PCS codes (discharges from October 1, 2015 - December 31, 2015) are in a separate set of files labeled Q4. More information about the changes to the HCUP databases for ICD-10-CM/PCS and use of data across the two coding systems may be found on the ICD-10-CM/PCS Resources page.