Digital Planimetry: Is it a Possible Standard Method for Evaluation and Measurement of Ulcer Healing?

Abstract

Introduction - The measurement of ulcers and the reduction of their surface, as an indicator of closure, are frequent procedures in the clinical and research fields. A medical record with digital support could provide greater precision and optimize the therapeutic approach. The primary aim of the study was to analyze the agreement in the measurement of lesions and presence of necrotic area between digital planimetry (MOWA® and HELCOS® systems) and manual planimetry (VISITRAK®), the latter being our reference pattern. The secondary aim was to analyze the degree of inter and intra-observer agreement. Methods - Design: Precision study of diagnostic method. Sample: 44 patients with chronic ulcers of different etiology. Variables studied: Total area (cm2) and percentage of necrotic area. Statistical analysis: Non-parametric correlation test (correlation coefficient r), Bland-Altman diagram and concordance and correlation index (CCI). A qualified nurse from our staff took photographs with the same camera, parallel to the lesion, using the same brightness and a calibrated reference point (2.5 cm2). Two observers independently measured the different variables with the three systems and one of them repeated the procedure in the following 24 hours. Results - The CCI for the total area between VISITRAK® / MOWA® was 0.89 (0.848- 0.92) and between VISITRAK® / HELCOS® was 0.79 (0.72- 0.85). The interobserver and intraobserver CCI (total area) was 0.99 (0.998- 0.996) and 0.76 (0.60- 0.86) for MOWA®, respectively. The interobserver and intraobserver CCI (total area) was 0.56 (0.35- 0.72) and 0.60 (0.35- 0.72) for HELCOS®, respectively. There was a low concordance between the different systems in the area of necrosis compared to the standard reference (VISITRAK®): r 0.58 and 0.23 for MOWA® and HELCOS®. Conclusion: The systems of digital image analysis present a high precision for the measurement of total ulcer area compared to the manual methods. However, the differentiation between the components of necrosis, granulation tissue and fibrin depends on the conditions of brightness and software parameters.