SEER-Medicare: Outcome and Assessment Information set (OASIS)

The Home Health Outcome and Assessment Information Set (OASIS) data included information that was collected for patients who are receiving skilled home health care. Patients receiving only personal care, homemaker, or chore services are excluded. OASIS assessments are collected at admission, specified time points for the purpose of improving home health care. The assessment is performed on admission, at 60-day intervals, following interruption of home care (e.g., hospitalization), and at discharge or death. The assessment is required for all adults age 18 or over who are Medicare and Medicaid patients. The OASIS assessment collects information in a standardized format about patients’ comorbidities, physical, psychological and psychosocial functioning in addition to the living arrangement.

Patients in the SEER-Medicare data diagnosed in 1999 and later have been linked with OASIS data from 1999 and later. Cancer patients with fee-for-service and HMO coverage are included. OASIS data is also available from 1999 and later for persons included in the SEER-Medicare 5% sample.

More details about the initial incorporation of OASIS data with SEER-Medicare is provided in: Thomas KS, Schwartz ML, Boyd E, Mariotto AB, White DP, Mariotto AB, Barrett MJ, Warren JL. Home Health Use Following a Cancer Diagnosis Among Patients Enrolled in Medicare Advantage and Traditional Medicare: Findings From the Newly Linked SEER-Medicare and Home Health OASIS Data. J Natl Cancer Inst Monogr. 2020 May 1; 2020 (55):53-59. [View Abstract] [Full Text]

View ResDAC’s Home Health Outcome and Assessment Information Set (OASIS) File Overview

View CCW’s Assessment: MDS Record Layouts and Codebooks