The article by Schein et al,1 published in the February 1994 issue of the Archives, illustrates the misuse of statistics that our college professors warned us about. Not only does this report directly contradict previously published reports by the same authors, it is also rife with internal inconsistencies.
The authors state that "... most of the risk associated with overnight wear is assumed to occur with as little as 1 to 3 nights of overnight wear." This statement is contradicted two paragraphs later when the authors attempt to explain the previously reported increased risk associated with disposable lenses2 as being due to longer periods of wear compared with other lens types. The statement also directly contradicts a principal conclusion of a previous large-scale multicenter study of risk factors for ulcerative keratitis written by several of the same authors.3
Ninety-three percent of case patients in the study by Schein
Epstein AB, Freedman JM. The Impact of Overnight Wear on the Risk of Contact Lens-Associated Ulcerative Keratitis. Arch Ophthalmol. 1994;112(11):1404-1405. doi:10.1001/archopht.1994.01090230014003