Percent Area Reduction (PAR) is a concept that wound care practitioners have been talking about for decades as a predictor of wound healing/surrogate endpoint. Well, set aside what you think you know about PAR. Check out this excellent blog by Zweli Tunyiswa which explores a debate about how best to use PAR when developing real-world wound care evidence.
Yes, PAR can be a valuable tool in clinical practice because when evaluated moving forward in time in the context of clinical care, it can help practitioners assess whether a wound is progressing as expected. Thus, PAR can be used as an indication we need to adjust the treatment plan. However, when wielding large real-world datasets for research, the use of PAR is not so straightforward. In clinical research, PAR (which must be measured over some specific time frame) is not the tidy surrogate for improvement/closure that we want to be believe it is. PAR over time is heavily influenced by factors such as baseline wound size, wound duration (age), and wound “type” (to name only a few of many factors). To advance the use of real world wound care data (particularly when trying to compare the effectiveness of treatments), we are going to have to have some nuanced and very careful conversations around topics we have taken for granted in the past – starting with PAR.
And while I am at it, think about this. Ignoring wound contracture, the only way that wound surface area gets smaller is via epithelialization. Epithelialization is actually one of the late phases in wound healing, after the wound has granulated (developed vascular tissue). As we extend clinical research to wounds with deep tissue exposure, PAR may not even be a relevant indicator of progress until many weeks have elapsed.
–Caroline
Dr. Fife is a world renowned wound care physician dedicated to improving patient outcomes through quality driven care. Please visit my blog at CarolineFifeMD.com and my Youtube channel at https://www.youtube.com/c/carolinefifemd/videos
The opinions, comments, and content expressed or implied in my statements are solely my own and do not necessarily reflect the position or views of Intellicure or any of the boards on which I serve.
