Wound debridement: Comparative reliability of three methods for measuring fibrin percentage in chronic wounds

The purpose of this study was to examine the intra- and interrater reliability of three methods to measure the percentage of fibrin within a wound, hence reflecting wound debridement. The three methods include visual assessment, a portable wound measurement system (PWMS) Visitrak(R), and a computerized planimetry software Canvas(R). The main objective was to compare the computerized planimetry with visual analysis. For each wound, a series of two repeated recordings of fibrin percentage based on the same Day 1 photograph at Day 8 and Day 15, respectively, was assessed by four evaluators using the two methods. Additional objectives consisted in the assessment of the inter-rater reliability of computerized planimetry and PWMS to assess fibrin percentage and total surface area. Twenty-four patients were included for a total of 31 wounds. Intraclass correlation coefficient revealed improved reproducibility and repeatability of computerized planimetry. The reproducibility of computerized planimetry was better than PWMS when measuring the percentage of fibrin and total wound area. Because average visual estimations were very close to the computerized planimetry, bedside evaluation of fibrin percentage and wound debridement was considered as reliable, and consequently a valid technique for daily practice. PWMS proved to be less convenient, owing to difficulties in identifying fibrin margins. The higher intra and interrater reliability of computerized planimetry probably reflected the fact that subjective clinical assessment and objective calculation of percentages were mandatory for correct wound evaluation. Therefore, digital image analysis was considered as an accurate method for double-blind and multicentric trials.