Two-dimensional wound measurement: comparison of 4 techniques.

Two- and three-dimensional wound measurement techniques are documented in the literature and used clinically, as well as in research. The purpose of this study was to compare 4 two-dimensional wound measurement techniques: linear length and width using a ruler, planimetry, computerized stereophotogrammetry (SPG) length and width, and computerized SPG area. Three plaster of Paris wound models were developed and baseline measurements of outer wound perimeters obtained via a Coordinate Measuring Machine. The convenience sample of raters included 66 upper-division baccalaureate nursing students, graduate nursing students, nursing staff, and wound care nurses. Each rater measured each wound twice in a randomly assigned order of methods written on a card drawn from an envelope. The least biased technique was the computer area, followed in order by the computer length and width, planimetry, and ruler length and width. The most accurate technique, given multiple raters, was determined by the standard error of measurement. The smallest standard error of measurement, thus the most accurate, was the computer area technique, followed in order by the ruler length and width, computer length and width, and planimetry. Interrater reliability of average ratings was high; only the SPG area measurements for single ratings were reliable enough for clinical or research purposes. Intrarater reliability was high for methods with low interrater reliability, suggesting that nurses are consistent in the direction of personal error.