Definition/Introduction

The Outcome and Assessment Information Set (OASIS) was primarily a suggestion of the Center for Health Services Research and Policy at the University of Colorado in 1994.[1] Shaughnessy et al formally proposed it as an assessment tool to measure outcome-based quality improvement for home health care (HHC) by measuring individual patient outcomes.[2] Home health agencies (HHAs) can use it to assess and improve the quality of care patients receive. Over 100 factors undergo evaluation once a patient enters HHC and at regular intervals until completion. The evaluations can be completed by a registered nurse, speech pathologist, or physical therapist.[3] OASIS is mandatory for all HHAs (or skilled care programs) with Medicare or Medicare-managed insurance. Functional health, physical improvement, and adverse events serve as outcome measures.

Issues of Concern

One of the challenges of OASIS is inter-rater reliability. Scores can be discordant due to the subjective nature of the evaluator's evaluation, interpretation, and experience. Inconsistent results are reflected in the Medicare Prospective Pay System reimbursement.[3] Multiple studies have tested the reliability and validity of OASIS. Tullai-McGuinness et al inspected the validity of OASIS for the activities of daily living, cognitive functioning, and depression by comparing it against the gold-standard interview-based instruments in the fields of gerontology and geriatrics used for clinical and epidemiological research. The results showed a good correlation between cognitive functioning and the activities of daily living between OASIS and the gold standard instruments. However, there was a low correlation in depression assessment.[4] 

Brown et al studied the detection of depression among HHC patients, and the primary outcome of the study suggested that depression is underdiagnosed among the elderly at HHC.[5] On January 1, 2008, the Centers for Medicare and Medicaid Services implemented the Home Health Resource Group (HHRG) scoring to overcome this problem. The clinician completes the HHRG scoring and assesses the severity, utilization of services, and functional status of the patients.[3][6] With this new model, there were 153 possible HHRG, compared with the 80 different possibilities before. Screening for depressive symptoms is now part of the criteria.

There have been several versions of OASIS implemented since 1991. The OASIS-D is the current one, effective January 1, 2019. The Centers for Medicare and Medicaid Services delayed the implementation of OASIS-E, originally scheduled to take effect on January 1, 2021, due to the COVID-19 pandemic. OASIS-E will delay until January 1 of the year that will be at least one full calendar year after the end of the pandemic. The updated version will include new standardized patient assessment data elements evaluating pain, comprehension, cognition, delirium, continence, self-care, mobility, and falls.

Clinical Significance

OASIS becomes essential as the assessment performed, preliminarily impacts how patient management will proceed. For instance, depression is one of the underdetected conditions of the HHC system of New York City. The Department of Health and Mental Hygiene found that if patients in HHC received adequate treatment, about 70% to 80% responded positively. If providers had adequate training, referrals for treatment would increase. Also, there should be sufficient coordination between providers and mental health services for the HHC have sufficient detection, treatment, and follow up for the patients.[7] When including symptoms of depression in screening with OASIS, which is mandatory, it increases the efficiency of diagnosing underlying depression in HHC patients and, at the same time, treating them.[5]

Nursing, Allied Health, and Interprofessional Team Interventions

Infection control is a challenge of HHC due to a lack of measurement methods. There are various areas where OASIS can help determine the course of treatment of the patient proposed. Because of its broad points of assessment, when used in the HHC setting, OASIS can help measure the rates of infection and increase the detection of infections.[8] OASIS helps to monitor surgical wounds and is a cost-effective resource to track the healing of wounds and prevent complications.

Consequently, OASIS has helped increase the discharge to home health from hospitals for wound infections.[9] Thus, with increased patients in HHC with surgical wounds, proper use of OASIS becomes essential for a better prognosis of the patients. With the same example of infections, every provider involved in patient care must have a role to play in managing the patient's health. Observational studies to measure the compliance of infection control policies by nurses showed high variation in different HHC organizations.[10][11]