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Outcome and Assessment Information Set (OASIS)
U.S. Department of Health and Human Services, Centers for Medicare & Medicaid Services (CMS).
The OASIS is a group of data elements that represent core items of a comprehensive assessment for an adult home care patient. Because OASIS can measure changes in a patient's health status between two or more time points, it forms the basis for measuring patient outcomes for purposes of outcome-based quality improvement (OBQI).
The general categories of data and health status items in OASIS include demographics and patient history, living arrangements, supportive assistance, sensory status, integumentary (skin) status, respiratory status, elimination status, neuro/emotional/behavioral status, activities of daily living, medications, equipment management, and information collected at inpatient facility admission or agency discharge.
Gender, age, race/ethnicity, State of residence, marital status, informal caregiver assistance, living arrangement, current payment sources for home care and health status.
U.S. adult, nonmaternity, home care patients receiving skilled services.
Mode of Administration
Completed by home health agency personnel.
Medicare and Medicaid certified agencies have been required to collect data since 1999.
Data Collection Schedule
Most OASIS data items are designed to be collected at start of care and every two months thereafter until and including time of discharge.
HHAs are required to electronically transmit OASIS data only for home care patients receiving Medicare and Medicaid skilled services to State survey and certification agencies. The State agencies have the overall responsibility for collecting OASIS data in accordance with CMS specifications. The State is also responsible for preparing OASIS data for retrieval by a national repository established by CMS.
National, State, agency.
The Home Health Care tables are based on OASIS assessment data from January 1 – December 31 in each year. The data for the measures are based only on home health episodes that began and ended in the same calendar year. Approximately 22% of patients have more than 1 episode in the same year.
For OASIS improvement measures, a person is not included if they are at the highest level and cannot improve any more. Similarly, a person is excluded from stabilization measures if they are at the lowest level and cannot decline any more. Consequently, the denominator for each of the measures can vary widely because of these definitions. On average, for example, only 30% of all episodes are included in the urinary incontinence measure and about 40 % for the confusion frequency measure, while 95% of episodes are included in bathing stabilization and about 83% of episodes for ambulation improvement.