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Past Topics
Growth Factors: Role and Function in Chronic Wound Care
Wound Healing and Cellular Communication
Proteases and the Chronic Wound
Bacterial Loads - Contamination, Colonization & Infection
Friend or Foe? The Role of Inflammation in Wound Healing
Perfusion - the Lifeline for Wound Healing
This Month

Challenges with OASIS and Wound Assessment

Assessment and Documentation Issues in Wound Care
The Environment of the Patient and The Healing Process
Examining the Environments of Wound Healing

Challenges with OASIS and Wound Assessment

Since the inception of the Prospective Payment System (PPS) in October of 2000, accuracy of wound assessment has become critical to the operation of home health agencies. Inaccurate wound assessment can effect reimbursement; cause inaccurate reporting of patient outcomes; and can create the appearance of potential adverse events.

In order for assessment to be accomplished in a consistent manner, clinicians must use the guidelines developed by the Wound Ostomy and Continence Nursing Society (WOCN) in answering the OASIS wound questions. You may access them by going to

Since the guidelines are too detailed to memorize clinicians should carry them with them and use them as a standard protocol for answering questions. Printing the guidelines on bright colored paper and putting them in plastic sleeves makes them easier to find and carry.

The OASIS instrument assesses pressure ulcers, venous ulcers, and surgical wounds. The assessment of these wounds is not comprehensive and also fails to identify other common wounds seen in home care such as skin tears and arterial ulcers. For these reasons a more comprehensive assessment of all wounds should be done on admission and weekly until discharge or wound healing has occurred. This assessment should include as a minimum wound location(s), size, type of tissue present, exudate, and the peri-wound area. This provides justification that the OASIS questions have been answered correctly and allows for discrepancies to be identified during supervisory review. For example, the clinician checks that the patient has a venous ulcer on the OASIS question but notes in the comprehensive assessment that the location of the ulcer is on the bottom of the foot. The supervisor reviewing the admission documentation can see there is a high probability of an inaccurate assessment since venous ulcers are seldom if ever located on the foot. Follow-up with the admitting clinician clarifies the information and allows for appropriate teaching and changes in diagnosis.

The 3M National OASIS Integrity Project released a report in November of 2003. Some important clarifications for OASIS wound assessment were incorporated into this document. A recommendation was made that staging a pressure ulcer be delayed for five days if the ulcer will become observable within that time period. This is sound advice since reimbursement for pressure ulcers is determined by the number of pressure ulcers at each stage and the stage of the most problematic pressure ulcer. Five days of enzymatic debridement may allow enough visualization of the wound bed to allow for staging or arrangements for sharp debridement may be made.

The report also clarifies that a patient continues to have a pressure ulcer even when healed if supported by clinical documentation in the record. In the case of a quadriplegic patient who has a history of a healed stage four pressure ulcer but no current ulcers, the stage four ulcer is the most problematic ulcer adding 36 points to the clinical domain. The status of the ulcer is fully granulating.

Caution needs to be taken when assessing the diabetic patient with a foot or leg ulcer. A clinical decision must be made as to the etiology of the ulcer. It can be due to neuropathy, pressure, venous or arterial disease. If due to neuropathy, clinical points are obtained when a primary diagnosis of diabetes mellitus with complications and a first secondary diagnosis of neuropathic ulcer is used. If due to pressure ie a heel ulcer in a bedridden patient then clinical points are obtained by answering the pressure ulcer questions. However, the primary diagnosis is also a pressure ulcer. If the wound is an arterial ulcer then points are not obtained through either the diagnosis or wound item questions. If the diabetic patient has a venous leg ulcer it is captured in the OASIS wound questions but the primary diagnosis is Venous Hypertension with Ulcer not Diabetes Mellitus.

The 3M report also clarifies how to properly assess surgical wounds. A muscle flap used to replace a pressure ulcer is considered a surgical wound. However, debridement of a pressure ulcer or a pressure ulcer treated with a skin graft is not considered surgical wounds. They remain pressure ulcers. Surgical wounds may be considered non healing the first four to five days after surgery if there is no palpable healing ridge. A healing ridge typically becomes palpable between day five and nine after surgery. Most newly admitted patients will be classified as having a non healing wound. This has implications for reimbursement as well as for improvement in surgical wounds being accurately reflected on Outcome Reports.

Education of staff regarding wound assessment is key to ensuring accuracy. CMS has developed free web based training at The site also provides links to the WOCN and other wound related sites. The 3M National OASIS Integrity Report should also be utilized in training.

This article was written by Deborah Diehl, RN, MSN, ANP, CWCN

3M National OASIS Integrity Project Report, Nov.1, 2003

Comprehensive Patient Assessment, OASIS "Think" and the OASIS "Walk", Fazzi Associates, Jan.2004

CMS Web Based Training

Doughty, D. Accurate Documentation of Wound Status under the OASIS System, The Remington Report, Sept/Oct 2001

The Wound & Skin Care Center is possible thanks to the generous support of Johnson and Johnson Wound Management Worldwide.

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