Measurement of the area of venous ulcers using two software programs 1

ABSTRACT Objective: to compare the measurement area of venous ulcers using AutoCAD(r) and Image Tool software. Method: this was an assessment of reproducibility tests conducted in a angiology clinic of a university hospital. Data were collected from 21 patients with venous ulcers, in the period from March to July of 2015, using a collection form and photograph of wounds. Five nurses (evaluators) of the hospital skin wound study group participated. The wounds were measured using both software programs. Data were analyzed using intraclass correlation coefficient, concordance correlation coefficient and Bland-Altman analysis. The study met the ethical aspects in accordance with current legislation. Results: the size of ulcers varied widely, however, without significant difference between the measurements; an excellent intraclass and concordance correlation was found between both software programs, which seem to be more accurate when measuring a wound area >10 cm². Conclusion: the use of both software programs is appropriate for measurement of venous ulcers, appearing to be more accurate when used to measure a wound area > 10 cm².


Method
This was a reproducibility study of evaluation tests. The study was conducted in a angiology clinic of a university hospital in southern Brazil, which treats patients with venous ulcers. The patients were selected according to the following inclusion criteria: age over 18 years, intact cognitive and verbal skills, presenting venous ulcers covering one side of the lower limb.
Five nurses who were participants in the skin wound study group of the hospital where the research was conducted, called evaluators, were responsible for data collection, which occurred from March to July of 2015. All nurses were trained in the process of obtaining the photographs and wound measurement. Both photographs were taken during the same care period. Next, the information was transferred to the researcher's notebook. The evaluator and the researcher performed the measurements of both photographs. This process was performed with all evaluators, always in pairs (researcher and one evaluator), until reaching the maximum number of individuals of the study population.
The data collection procedure occurred according to the following protocols.
-Protocol for obtaining photographs of wounds: after cleaning the wound with 0.9% saline solution, a surgical compress was placed under the lower limb with the ulcer, in order to give a white background color for the picture; a black square with three centimeters printed in on A4 sheet was placed close to the ulcer, to be considered as a reference object. The photograph was taken with a Fujifilm Camera FinePix S14 megapixels (f/6.4, ISO 400, enabled macro function, automatic white balance, high sharpness, and flash disabled). The camera was perpendicular to the wound (90°), and 50 cm away from the wound, bringing it closer to or farther away from the wound, as necessary.
-Protocol for wound area measurement using the published in 2012 (6) .
Data were uploaded into Microsoft Office Excel ® , using duplicate, independent entry in order to correct any typographical errors. For the statistical treatment of the area of the venous ulcers, mean and standard error were used. In order to identify the normality of the data distribution, the Shapiro-Wilk test was applied; due to lack of data normality, the Wilcoxon test was used in order to identify differences between the measurements, and to verify the degree of systematic differences between measurements in pairs (researcher and evaluator).
The distribution of the differences between the measures and the mean difference between them was analyzed (8) . The reproducibility was measured using the intraclass correlation coefficient (ICC) and concordance Eberhardt TD, Lima SBS, Lopes LFD, Borges EL, Weiller TH, Fonseca GGP.

Results
The study participants (n = 21) had a mean age of 60.9 years, and nine (42.9%) were aged 64-72 years; the majority were male (66.7%). The number of venous ulcers ranged from one to five per patient, with a median of 1.8, totaling 36 venous ulcers (Figure 1).

Discussion
The sizes of ulcers varied widely; however, there was no statistically significant difference between the measurements. Other studies that characterized patients with venous ulcers in outpatient care also found wide range of wound sizes (10)(11)  Another study (5) that compared the AutoCAD ® software with another program also found that marking offsets, the relative point of view, is larger in wounds with a smaller area, since it requires hand movements of the operator.
One study (12) compared three methods of pressure ulcer area measurement -ruler, tracing paper with graduated acetate, and digital planimetry; it found that all three methods were appropriate for measuring the surface area of small circular wounds (area ≤ 10 cm²); however, in irregularly shaped wounds > 10 cm², the ruler overestimated the size.