In response:

Thank you, Dr Bolton, for your insightful letter related to wound measurement. You raise good points that are yet to be addressed in wound measurement research. As you noted, goals of wound measurement can include monitoring percent change in wound area over time, prediction of healing time for a wound, or research purposes. The purpose of our study was to ascertain the most accurate linear wound measurement technique (least overestimation of actual wound area), regardless of wound shape, for the bedside practitioner. The second goal was to identify an accurate method that provided clear directions for standardization between measurers.

You note that the technique of longest length x longest width, regardless of body axes, showed greater interrater reliability among clinicians and has been shown to effectively predict healing. We would note that the issue of overestimation of actual size (accuracy) was not addressed, as most studies did not have actual wound area measurements. The study we reported on did have actual area measurements of the 3 wound models and compared 4 different linear methods to measure wound length and width and then estimate area. The technique of longest length x longest width at any angle, regardless of head-to-toe orientation, overestimated actual wound surface area by the greatest percent. The method that overestimated actual area the least (for all 3 wound shapes) was the technique of head-to-toe longest length x side-to-side longest width, perpendicular to one another. This method supplies the most explicit directions to the one who does the measuring, and it is important to be able to compare over time the measurements done by multiple health care professionals and with the patient in varied positions. The researchers therefore recommended using this technique for the bedside practitioner for greater accuracy in estimating actual area and consistency between measurers.

The authors further recommend that future studies should address both the accuracy of linear measurements, based on actual wound area versus measured wound area, as well as interrater reliability. We must strive to be both valid and reliable.

The authors thank you for your comments.

Diane Langemo, PhD, RN, FAAN

Julie Anderson, PhD, RN, CCRN

Darlene Hanson, MS, RN

Susan Hunter, MS, RN

Patricia Thompson, MS, RN

Grand Forks, ND