To the Editor.—Mertz and Eaglstein1 concluded that microorganisms in wound beds that are covered with a semiocclusive film dressing multiply and survive better than microorganisms in wound beds that are allowed exposure to air. Although I sympathize with these conclusions, the reported study had several significant flaws.
First, the authors placed 30 wounds on a single pig. Wound locations were not specified but are of critical importance, as the animal must not be able to lick the wounds that are left exposed to air. It is not acceptable to require the reader to assume that this restriction was satisfied.
Second, there were problems with the reported statistical techniques. An analysis of variance for repeated measures is inappropriate, because each wound was analyzed independently and only once. If an analysis of variance of any sort were to be used, Student's t test (which applies only to the two-sample design)
DANIEL M. STRICKLAND. Inadequacies in a Wound Infection Study. Arch Surg. 1984;119(11):1347–1348. doi:10.1001/archsurg.1984.01390230111029