OASIS inter-rater reliability and reimbursement: a study of inter-rater reliability of the Outcome and Assessment Information Set (OASIS): its effects on the Home Health Resource Group (HHRG) and reimbursement.

One of the outcomes of the initial Outcome and Assessment Information Set (OASIS) is to establish a level of reimbursement through the Medicare Prospective Payment System (PPS). Several inter-rater reliability (IRR) studies have noted differences in responses to individual questions within the OASIS but little is known about how variations in scoring might affect the final reimbursement projection. In a one-way repeated measures design study, the OASIS was completed on 52 patients by both an RN and a PT within a 24-hour timeframe and the projected reimbursement rates were compared. Fifty-four percent of the outcomes of the assessment pairs were identical; differences in the remaining 46% were equally divided between RNs and PTs in projecting a higher reimbursement rate and with similar distributions. The mean difference in projected reimbursement rates was $16.43 per episode with no significant difference between the PT and RN Home Health Resource Group (HHRG) distributions.