Waterlow Score Calculator

This health tool represents a pressure ulcer risk assessment and can be used as a prevention tool. It is based on the Waterlow assessment, which is the most used in the UK clinical system.

The score is intended to be used by nurses in the evaluation of patients which present a potential for developing pressure sores in the setting of hospitals, nursing and residential homes.

The original tool devised by Judy Waterlow in 1985 contains the risk assessment and a guide on nursing care and main prevention means. These are all adapted according to the levels of risk status from the score.

Female (2 points)

Male (1 point)

14 – 49 (1 point)

50 – 64 (2 points)

65 – 74 (3 points)

75 – 80 (4 points)

81 + (5 points)

Average BMI: 20 – 24.9 (0 points)

Above average BMI: 25 – 29.9 (1 point)

Obese BMI: >30 (2 points)

BMI: 15 kg (4 points)

No (0 points)

Yes (1 point)

Terminal cachexia (8 points)

Multiple organ failure (8 points)

Single organ failure (Resp, Renal, Cardiac) (5 points)

Peripheral vascular disease (5 points)

Anemia (Hb 2 hours (5 points)

On table >6 hours (5 points)

1 drug (1 point)

2 drugs (2 points)

3 drugs (3 points)

4 or more drugs (4 points)

In the hospital setting, the Waterlow scale, as the score is sometimes referred to, is collected routinely and can provide useful information (patient status and evolution) on postoperative morbidity and mortality. For example, it is used in the case of stroke patients recovery.

When collected for the first time, it should be performed within 4 hours of admission. Some specialists consider that the score can be simplified and improved by removing the gender item.

Obtainable scores range between 0 and 49. The Waterlow score is interpreted in the following way:

■ 9 or less: Patient presents little to no risk;

■ 10 – 14: Patient is at risk;

■ 15 – 19: Patient is at high risk;

■ 20 and above: Patient is at very high risk.

The recommendation is that the assessment results are recorded and monitored in time and that the score is not solely relied upon, clinical judgement having to come before any scoring, like with most risk assessment tools.

This brings the discussion to one of the main criticisms received by the model, the fact that it wasn’t found, in a research setting, to display high levels of reliability and validity. In other cases, it was found to over-predict pressure ulcer formation.

A systematic review concluded that the score offers a high sensitivity score (82.4%) but has low specificity (27.4%).

According to the European Pressure Ulcer Advisory Panel (EPUAP), which advocates for pressure ulcer prevention, there are 4 grades of severity.

■ Grade 1 pressure sore – characterized by a discoloration of the skin, otherwise intact. The skin is not affected by light pressure (non-blanching erythema).

■ Grade 2 pressure sore – characterized by artial thickness skin loss or some damage involving epidermis and sometimes dermis. The injury is still superficial and can be similar to an abrasion or a blister.

■ Grade 3 pressure sore – characterized by skin loss in the thickness of the skin with damage of the subcutaneous tissue. There is no extension of the injury into the underlying fascia.

■ Grade 4 pressure sore – characterized by lesions of full skin thickness that present destruction and necrosis of the underlying tissue.

Pressure ulcer prevention is one of the high impact actions in the duties of nurses in different health settings. Some of the most common and efficient prevention strategies include frequent turning of the patient, quality mattresses, use of toppers and bed systems. Other recommendations include:

■ General hygiene measures such as frequent hand washing;

■ Appropriate nutrition (high protein, vitamins);

■ Comfort aides such as pillows;

■ Pain medication if needed.

1) Waterlow JA. (1995) Reliability of the Waterlow score. J Wound Care; 4(10):474-5.

2) Edwards M. (1995) The levels of reliability and validity of the Waterlow pressure sore risk calculator. J Wound Care; 4(8):373-8.

3) Anthony D, Reynolds T, Russell L. (2003) A regression analysis of the Waterlow score in pressure ulcer risk assessment. Clin Rehabil; 17(2):216-23.

4) Griffiths P, Jull A (2010) How good is the evidence for using risk assessment to prevent pressure ulcers? Nursing Times; 106: 14, early online publication. 

5) Thorn CC, Smith M, Aziz O, Holme TC. (2013) The Waterlow score for risk assessment in surgical patients. Ann R Coll Surg Engl; 95(1):52-6.

6) Lyder CH, Ayello EA. Pressure Ulcers: A Patient Safety Issue in Patient Safety and Quality: An Evidence-Based Handbook for Nurses.

7) Pancorbo-Hidalgo PL, Garcia-Fernandez FP, Lopez-Medina IM, Alvarez-Nieto C. (2006) Risk assessment scales for pressure ulcer prevention: a systematic review. J Adv Nurs; 54(1):94-110.