Wound measurement: The comparative reliability of direct versus photographic tracings analyzed by planimetry versus digitizing techniques

Objective: To investigate two methods of wound measurement (planimetry and digitizing) performed on two routinely used techniques of clinical wound as sessment, tracings taken directly from a patient's wound (raw tracing) and from photographs of the wound (photographic tracing). Design: We examined the level of repeatability and thus reliability of thes e methods, and determined if absolute measured wound size differed between the combinations of method and assessment procedures. Patients: Seven patients (4 women, 3 men; mean age +/- standard error of th e mean = 63.1 +/- 5.0yrs) with a total of 11 wounds. Setting: Patients attended a podiatry outpatient department on two separate days for raw and photographic tracing of their wounds. For both of these t race types, a series of repeated recordings were conducted by a single inve stigator using planimetry and digitizing measurement methods. Main Outcome Measure: Independent statistical analyses (analysis of varianc e, p < .05) were conducted on logged coefficients of variation and logged m eans data to investigate for repeatability and for size differences, respec tively. Results: Planimetry produced a significantly larger degree of variability ( thus less repeatability) than digitizing(p = .02) and also produced smaller readings (p = .00001), Averaging over methods also indicated that photogra phic tracings produced smaller readings than raw tracings (p = .019), Conclusion: For the wound sizes and shapes examined, tracings taken directl y from the patients were found to be an inexpensive clinical and research a ssessment tool on which digitizing was conducted with a higher level of rep eatability than planimetry. Further research is needed to determine if the current findings apply to a wider population within wound management clinic s.