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What is an OASIS reviewer?

by Keith Grunig

What is OASIS and what does an OASIS reviewer do?


Home Health Nurse


If you deal with home health and Medicare, you will deal with OASIS.  Many people don't understand what OASIS is and what it is used for.  OASIS stands for Outcome and Assessment Information Set.  Basically, OASIS is a bunch of information about a patient that describes the actual condition of the patient at the time of assessment, provides data to CMS about that patient, and allows CMS to track outcomes using a standard method and data set.  CMS uses this data in multiple ways.  CMS tracks each patient's OASIS data across the episode(s) to determine the quality of care that the patient receives from the home health agency (HHA).  CMS also uses data to determine reimbursement rates, therapy utilization, days on service, patient improvement (or decline), death, etc.  In fact, PDGM was determined almost exclusively off of the data that HHAs gave to CMS using OASIS.   Many agencies were discharging patients before 30 days but were taking 60 days’ worth of reimbursement.  CMS noticed this and adjusted PDGM to two 30-day episodes rather than a single 60-day episode.  OASIS is periodically updated to reflect new questions or areas of emphasis about which CMS wants to collect data. 

What does an OASIS Reviewer actually do?

Home Care Answers' employees are OASIS reviewers.  An OASIS reviewer should be certified using one of the recognized certification programs that tests a reviewers knowledge about OASIS.  There are a few different types of certification.  Those are a few different OASIS certifications that are essentially testing the same information, but are accredited through different organizations.  One certification is called COS-C, which is called Certificate of OASIS Specialist- Clinical.  Another certification is COQS, which is just through a different organization.  

An OASIS reviewer is typically a nurse- but could be another clinical specialty such as physical therapist.  The main responsibility is to ensure accuracy on OASIS and remain compliant. The reviewer will review the relevant documentation on each chart including referral, History and Physical, clinical summaries, and visit notes from various disciplines.  After the reviewer has a good understanding of the patient's history, the reviewer then looks at the answers the clinician who gathered the OASIS provided.  The reviewer compares the documentation to the OASIS and then highlights omissions or areas where the documentation does not support the OASIS response.  For example, a question on OASIS M1242 assess pain impacting movement.  If a patient had a recent fall and fractured his/her femur 4 days ago, a clinician may respond that the patient feels no pain.  This is likely not correct, perhaps the patient is on pain medication and pain isn't significant, but it would be if no medication had been taken.  The reviewer could suggest a change to say that pain frequently interferes with daily tasks.  The reviewer will then compile all of the changes for each OASIS and show to the clinician who can then agree or disagree with the suggested changes.

Here is a link on what the COS-C test is:



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