Objectives: To assess the association between planimetric wound area and simple wound measurements. To ascertain the applicability of planimetry-based research to clinical practice.
Design: A retrospective cohort study of 260 consecutive patients followed up for at least 24 weeks.
Setting: Outpatient dermatology department of a major medical center.
Intervention: Wounds were measured using computer-based planimetry and were treated according to a standard protocol for venous leg ulcers.
Patients: Two hundred sixty patients with venous leg ulcers.
Main outcome measures: Complete ulcer healing at 24 weeks.
Results: Using the Pearson, Spearman, and Kendall correlation coefficients, we found a tight correlation between planimetric wound area and wound width, length, width x length, perimeter, and area based on the formula for an ellipse. The values for all correlation coefficients were greater than 0.80 (P < .001 for all associations). Width, length, length x width, and elliptical area measurements all correlated closely with failure to heal (P < .001). The correlation between simple values and planimetric area dropped considerably for wounds more than 40 cm2, which represented 6% of the wounds in this study.
Conclusions: The equivalence between simple and planimetric wound measurements allows for the extrapolation of wound measurements from clinical trials to clinical practice, and suggests that simple wound measurements may confidently be used as predictors of healing in the clinical setting.