The HCUP Michigan inpatient files were constructed from the Michigan Health and Hospital Association (MHA) inpatient stay files.

Michigan supplied discharge abstract data for inpatient stays from general acute care and specialty hospitals (e.g., rehabilitation hospitals) that are a member of the Michigan Health and Hospital Association.

Not all hospitals report a full calendar year of data. Some hospitals close during the year; other hospitals have technical problems that prevent them from reporting a full year.

Stays in special units within the hospital (e.g., psychiatric, rehabilitation, long-term care) are not included in the Michigan file.

Three types of records were excluded from the HCUP Michigan inpatient data:

• Records that were marked as replicated by the data source were excluded from the HCUP Michigan file. If the hospital was unable to submit data, MHA replicated the data, either from a previous year or the current year. MHA included a flag on the discharge records that indicated if the record was replicated:
• In 1999, 4,928 replicated records were excluded.


• In 2000, 17,636 replicated records were excluded.


• In 2001, 4,928 replicated records were excluded.
• Records from non-Michigan hospitals were deleted during HCUP data processing:
• In 1999, three out-of-state hospitals were excluded.


• In 2000, three out-of-state hospitals were excluded.


• In 2001, eleven out-of-state hospitals were excluded.
• Records with a discharge disposition of "still a patient" were excluded from the HCUP Michigan file.