A reliable method of determining wound healing rate.

Several wound healing rate measures have been introduced with the main goal of enabling quantification of the effects of various therapeutic modalities on the healing of open wounds. Different definitions of wound healing rate render comparison of clinical results difficult. The goal of the present study was to propose a measure of wound healing rate that is independent of initial wound extent and to present a method of wound healing rate prediction. Comparisons were made of wound healing rate defined as absolute area healed per day, percentage of initial area healed per day and advance of the wound margin towards the wound centre per day. Analysis was performed on 300 wound cases. A disadvantage of wound healing measures that either use absolute area healed per day or percentage of initial area healed per day is their very limited use for comparing healing rates of wounds with different initial sizes. This disadvantage was overcome by incorporating a wound perimeter; thus obtaining a measure of the advance of the wound margin towards the wound centre. A definition of healing rate expressed as the greatest average wound margin distance from the wound centre divided by the time to complete wound closure is proposed. Because not all wounds are closed in the observation period, the time to complete wound closure has to be predicted. A method of wound healing rate prediction is presented based on a delayed exponential model the parameters of which are obtained from at least five weekly wound area measurements. Paired t-tests between actual time needed to complete wound closure and the predicted time resulted in p = 0.062 after four, 0.484 after five and 0.900 after six weeks of observation.