Waterlow Scale

Clinical Summary

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Tool Description

  • used to assess the risk for pressure ulcer development.
  • created to provide better sensitivity and specificity than the Norton by increasing the number of items used. Every patient is evaluated on 8 items:
    1) Age
    2) Sex
    3) Body build
    4) Appetite
    5) Continence of urine and feces
    6) Mobility
    7) Skin appearance in risk areas
    8) Special risks (disorders associated with tissue malnutrition, neurological deficits, medication, recent surgery or trauma)

ICF Domain:

Body Function – Subcategory: Functions of the Skin

Number of Items:

8

Brief Instructions for Administration & Scoring

Administration:

  • clinician-administered; raters indicate client status based on personal knowledge of the client or chart review.
  • Items are scored as either dichotomous (yes/no) or on domain specific scales that range from 0-1 to 3-5. Domains are scored based on descriptive criteria provided on the scoring sheet (for example, ‘body build’: average – 0; above average – 1; obese – 2; below average - 3). 
  • Administration time is usually 5-10 minutes.

Equipment: None.

Scoring:

  • Scores are totaled to produce a summary score from 3 (best prognosis) to 45 (worst prognosis).

Interpretability

MCID: not established
SEM: not established
MDC: not established

  • Interpreting scores is difficult given lack of detail in item descriptions.
  • Scores of 10+ denote risk of developing a pressure ulcer, 15+ high risk and 20+ very high risk. No rationale is provided for how these numbers were determined.
  • No normative data or cut-points have been established for the SCI population
  • Published data for the SCI population is available for comparison (see the Interpretability section of the Study Details sheet).

Languages:

English.

Training Required:

None but reading the manual is recommended.

Availability:

See the how-to page of this tool.

Clinical Considerations

  • The Waterlow scale is quick and easy to use screen that provides predictive information about the risk of developing a pressure sore. 
  • The scale omits items previously found to be important predictors of pressure ulcer development for people with SCI in acute and rehabilitation settings. The reliability of the scale has not been demonstrated with a SCI population, but poor inter-rater reliability has been reported in other populations.
  • The scale is easy to score and administrate with no patient burden.

Measurement Property Summary

# of studies reporting psychometric properties: 2

Reliability:

No values were reported for the reliability of the Waterlow scale for the SCI population.

Validity:

  • The Waterlow scale was significantly and poorly correlated to the Stirling’s ulcer severity scale whether the scales were treated as continuous variables (Spearman’s r=-0.28) or categorical variables (Spearman’s r=0.32).
  • ROC analysis yielded an AUC of 76 (95% CI: 68-84).

[Wellard 2000, Ash 2002]

Responsiveness:

No values were reported for the responsiveness of the Waterlow Scale for the SCI population at this time.

Floor/ceiling effect:

  • 64% of patients were reported to be high risk, while the remaining 36% of patients were reported to be at very high risk.

[Wellard 2000]

Reviewer

Dr. Janice Eng, Christie Chan

Date Last Updated:

Feb 1, 2013