- Used to describe the severity of pressure ulcers.
- Derived from previously published UK scales developed by a consensus panel of national tissue viability experts. This observational scale has 5 stages ranging from stage 0 to stage 4, where:
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
4 - full-thickness skin loss with extensive destruction and tissue necrosis extending to bone, tendon or capsule.
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.
Body Function – Subcategory: Functions of the Skin
Number of Items:
Brief Instructions for Administration & Scoring
- 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.
- The scale has 5 stages (0-4), where zero represents no clinical appearance and four indicates full thickness skin loss with extensive destruction extending to bone, tendon or joint capsule.
- The two digit version includes more detailed ulcer descriptors.
- 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.
- Published data for the SCI population is available for comparison (see Interpretability section of the Study Details sheet).
To ensure basic understanding of skin and soft tissue anatomy and relevant physiological concepts, practitioners should undergo training prior to using the scale.
See the how-to page of this tool.
- 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 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 criteria may be masked by the skin pigment.
Measurement Property Summary
# of studies reporting psychometric properties: 1
No values were reported for the reliability of the Stirling’s Ulcer Severity Scale for the SCI population.
- When the scales were treated as continuous variables, there were significant and low correlations between the Stirling scores and both the Norton (Spearman’s r=-0.28) and the Waterlow scores (Spearman’s r=0.38), but not the Braden scores.
- When the scales were treated as categorical variables (at risk, high risk, very high risk), only the Waterlow scores were significantly correlated to the Stirling scores (Spearman’s r=0.32).
No values were reported for the responsiveness of the Stirling’s Ulcer Severity Scale for the SCI population.
No values were reported for the presence of floor/ceiling effects in the Stirling’s Ulcer Severity Scale for the SCI population.
Dr. Vanessa Noonan, Marzena Zhou
Date Last Updated:
Feb 22, 2017
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The 2-digit Stirling Scale is rated out of 4 stages with subratings in each stage.
The 1-digit Stirling Scale is simply the 4 stages with no subratings.
Stage 0: No clinical evidence of a pressure sore.
0.1 Normal appearance, intact skin
0.2 Healed with scarring
0.3 Tissue damage, but not assessed as a pressure sore.
Stage 1: Discoloration of intact skin (Light finger pressure applied to the site does not alter the discoloration).
1.1 Non-blanchable erythema with increased local heat.
1.2 Blue/purple/black discoloration. The sore is at least stage 1.
Stage 2: Partial-thickness skin loss or damage involving epidermis and/or dermis.
2.3 Shallow ulcer, without undermining of adjacent tissue.
2.4 Any of these with underlying blue/purple/black discoloration or induration. The sore is at least stage 2.
Stage 3: Full-thickness skin loss involving damage or necrosis of subcutaneous tissue but not extending to underlying bone, tendon or joint capsule.
3.1 Crater, without undermining of adjacent tissue.
3.2 Crater with undermining of adjacent tissue.
3.3 Sinus, the full extent of which is unknown.
3.4 Full-thickness skin loss but wound bed covered with necrotic tissue (hard or leathery black/brown tissue or softer yellow/cream/grey slough) which masks the true extent of tissue damage. The sore is at least stage 3. Until debrided it is not possible to observe whether damage extends into muscle or involves damage to bone or supporting structures.
Stage 4: Full-thickness skin loss with extensive destruction and tissue necrosis extending to underlying bone, tendon or joint capsule.
4.1 Visible exposure of bone, tendon or capsule.
4.2 Sinus assessed as extending to bone, tendon or capsule.
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.