The Outcome and Assessment Information Set (OASIS) is used for outcome reporting, quality improvement, and case mix adjustment of per-episode payment for home health care. The research described here addresses interrater reliability of OASIS items and compares clinician time required to complete patient assessment with and without OASIS. Interrater reliability for OASIS data items was estimated using independent assessments by two clinicians for a sample of 66 patients. Incremental assessment time due to OASIS was estimated using interview data from two agency-matched groups of clinical care providers-one group who used OASIS in the assessment and a second group whose assessment did not include OASIS items. Interrater reliability is excellent (kappa > .80) for many OASIS items and substantial (kappa > 0.60) for most items. The reported time required to complete an assessment with OASIS did not differ from the time required for a comparable assessment without OASIS. The results of this study are being used to guide developmental efforts to improve OASIS items. They can also be informative to home health care agencies when interpreting OASIS-based outcome and case mix reports.
Keywords: Medicare; Outcome measurement; case mix measurement; interrater agreement; prospective payment; quality improvement.