LAUSR

The aim of the study was to assess the reliability of measuring the cross‐sectional area of diabetic foot ulcers using Image J software. The inter‐ and intra‐rater reliability of ulcer area measures were assessed using digital images of acetate tracings of ulcers of the foot affecting 31 participants in an off‐loading randomised trial. Observations were made independently by five specialist podiatrists, one of whom was experienced in the use of Image J software and educated the other four in a single session. The mean (±SD) of the mean cross‐sectional areas of the 31 ulcers determined independently by the five observers was 1386·7 (±22·7) mm2. The correlation between all pairs of observers was >0·99 (P < 0·001). There was no significant difference overall between the five observers (ANOVA F1.538; P = 0·165) and no difference between any two (paired samples test t = −0·787–1·396; P ≥ 0·088). The correlation between the areas determined by two observers on two occasions separated by not less than 1 week was very high (0·997 and 0·999; P < 0·001 and <0·001, respectively). The inter‐ and intra‐reliability of the Image J software is very high, with no evidence of a difference either between or within observers. This technique should be considered for both research and clinical use in order to document changes in ulcer area.