The Stirling’s Pressure Ulcer Severity Scale is used to describe the severity of pressure ulcers (Pedley 2004). The scale has several variations, with the most common being the 1 and 2-digit scales, where the nature and severity of the ulcer are graded.

Number of items: N/a

Procedure/Administration: Using the 1-digit scale, raters indicate the severity of the ulcer from 0 to 4, according to the stage definitions. Using the 2-digit scale, raters indicate the severity of the ulcer according to the stage definitions and specific descriptors. For example, for stage 0 there are three descriptors, 0.1 - normal appearance, intact skin; 0.2 - healed with scarring, and 0.3 - tissue damage, but not assessed as a pressure sore.

How scored: The scale has 5 stages (0 = no clinical evidence of a pressure sore; 1 = discoloration of the intact skin, 2 = partial-thickness skin loss or damage involving epidermis and/or dermis; 3 = full-thickness skin loss involving damage or necrosis of subcutaneous tissue but not extending to underlying bone, tendon or joint capsule; and 4 = full-thickness skin loss with extensive destruction and tissue necrosis extending to bone, tendon or capsule). The two digit version includes more detailed ulcer descriptors.

Interpretability: Differentiation between the grade descriptors depends on clinical identification of the tissues. Differentiation requires not only observing the wound bed, but also having sufficient knowledge to distinguish the different tissue layers. The higher the grade of the ulcer, the greater the severity of the ulcer.

Acceptability: The measure was derived from previously published UK scales developed by a consensus panel of national tissue viability experts.

Languages: English

Usability:  The Stirling scale is easy to use, has good ulcer description, and good choice of descriptors. The descriptors in the 2-digit version enable a more accurate grading in comparison to other pressure ulcer severity scales. However, because the stage 1 descriptor of the scale focuses on skin discoloration, the validity of the Stirling scale is questionable when used with dark-skinned patients as this criterion may be masked by the skin pigment.  And, as with all pressure ulcer grading scales, this scale is open to bias and subjectivity.

Time to administer: No information was found on how long it takes to use the scale.

Time to score: N/a

Training required: To ensure basic understanding of skin and soft tissue anatomy and relevant physiological concepts, practitioners should undergo training prior to using the scale. 

Availability: The2-digit and 1-digit scales can be found in Pedley 2004

Equipment required: N/a

Summary: Observational pressure ulcer grading scales are open to bias and subjectivity resulting from individual interpretations. These interpretations reflect clinician knowledge and ability to identify anatomical structures and changes. The 2-digit version has greater range of descriptors than the 1-digit version, which makes grading easier and provides a more accurate and clinically meaningful description of the damage (Pedley 2004).

Psychometric Summary

Note: TR= Test re-test; IC= Internal Consistency;Inter-O=Inter-observer; Intra-O=Intra-observer; SS=Sensitivity/Specificity.

Red light= A single study involving SCI subjects which has less than adequate findings of reliability, validity, and/or responsiveness.

Yellow light= A single study involving subjects with SCI which has adequate to excellent findings of reliability, validity, and/or responsiveness.

Green light= At least 2 studies involving subjects with SCI which have adequate to excellent findings of reliability, validity, and/or responsiveness.

N/a= No information.

References

• Pedley GE. Comparison of pressure ulcer grading scales: a study of clinical utility and inter-rater reliability. International Journal of Nursing Studies 2004;41:129-140.
• Wellard S, Lo SK. Comparing Norton, Braden and Waterlow risk assessment scales for pressure ulcers in spinal cord injuries. Contemp Nurse 2000;9:155-160.