Norton Score For Pressure Ulcer Risk

Norton score explained

The Norton score was created in 1962 by Norton as the first pressure sore risk evaluation method. Initially, it was intended for use within the geriatric hospital population.

Five parameters have been taken into account, each with answer choices that describe the status of the patient on a scale.

The severe items are awarded the least number of points, therefore, scores closer to 5 (the minimum Norton score) are indicative of a severe outcome.

The following table introduces the Norton score:

The score has been praised for its quick and simple administration. Has been validated with a result of 60.8% accuracy in predicting pressure ulcer development.

The sensitivity is of 5.8% whilst the specificity goes up to 95.6%.

The minimum detectable change MDC or the MCID or SEM have not been established.

The main limitation of the score is the fact that it overlooks risk factors in the development of pressure ulcers in patients with spinal cord injury (SCI) or stroke.

Some of these risk factors include:

■ The extent of the paralysis;

■ Severe spasticity;

■ Serum creatinine;

■ Pulmonary, cardiac or renal disease.

This means that the score lacks the required specificity and sensibility to be used in SCI patients.

Currently, a score that is gaining more and more popularity is the Braden scale which is based on patient characteristics which have not been previously taken in account, such as sensory perception, skin wetness or nutrition status.

It is important to note that such risk assessment tools should not replace clinical judgment.

Score interpretation

Each of the 5 items in the Norton score is awarded a number of points, from 1 to 4, depending on the severity of patients condition.

Therefore, the final score ranges from 5 to 20, where 5 indicates maximum sore risk and 20 indicates that the patient is unlikely to develop pressure ulcer.

The general rule for interpreting the result states that the higher the score, the better prognosis the patient has.

The original study has defined a cut off point at 14. Scores below 14 carry a high pressure ulcer risk while scores below 14 indicate a low risk.

The following table introduces specific risk categories, correlated with Norton scores.

Original study

Norton D. (1962) An Investigation of geriatric Nursing problems in hospitals. London. National corporation for the care of Old People (now the centre for Policy on Ageing)

Other references

1. Balzer K, Pohl C, Dassen T, Halfens R. The Norton, Waterlow, Braden, and Care Dependency Scales: comparing their validity when identifying patients' pressure sore risk. J Wound Ostomy Continence Nurs. 2007; 34(4):389-98.

2. Cullum N, Deeks JJ, Fletcher AW, Sheldon TA, Song F. Preventing and treating pressure sores. Qual Health Care. 1995; 4(4): 289–297.