To the Editor:

I am writing in response to the article titled "Measuring Wound Length, Width, and Area: Which Technique?" which was published in Advances in Skin & Wound Care (January 2008). First, I would like to congratulate the authors on a worthy goal of providing practitioners with evidence-based recommendations for measuring wound size and adding perspective with further evidence. Wound measurement techniques ideally match the goal of measurement. For example, a research study exploring wound responses to drug dosage per centimeter squared of wound area would require precise, accurate wound area measurements at each point in time, such as those obtained by tracing, counting area units, using planimetry, or performing image analysis.

If the goal is to predict healing time of a wound entering one's practice, geometric area estimates based on simple longest length x longest perpendicular width measurements have been validated (P < .05) in a clinical cohort of 260 wound patients as an effective measure of total wound area and as a strong predictor of wound healing.1

Other clinical goals usually involve monitoring percent change in wound area over a period of time to benchmark wound progress across the continuum of care,2 optimize clinical feedback about wound progress and wound healing outcomes,3 monitor progress to meet government requirements,4 such as F-Tag 314, prevent or allay litigation concerns, or flag nonhealing wounds to improve care before disaster ensues.5-9

Percent change in wound area over time accurately and effectively documents progress2,4-9 and, during the first 2 to 4 weeks of care, provides a simple, reliable, valid early warning that diabetic foot ulcers,5 pressure ulcers,6 and venous leg ulcers7-9 are unlikely to heal in 12 to 24 weeks of the same care. This enables clinical professionals to implement early action to improve diagnosis or care for a nonresponding or deteriorating wound.

Although length x width is not perfectly accurate in measuring wound area, it has been validated to reflect wound area1 and its percent change over time5 only if estimated from measurements of longest length and longest perpendicular as width. Wound area measurements based on body axes have been reported elsewhere as less reliable than those based on geometric length and width10 and would experience added error of measurement over time during clinical use as wounds change in shape and orientation along the body axis during healing.

In conclusion, if predicting or monitoring wound progress is the goal of wound measurement, area or percent change in wound area over time (based on longest length x longest perpendicular width wound measurements) seems an evidence-based option in which those using a ruler can be confident. Substantial clinical evidence supports reliability and validity of using these simple measures to track wounds across the continuum of care and provide feedback to keep patients on the path toward healing.

Laura Bolton, PhD, FAPWCA

New Brunswick, NJ

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