[Skip to Content]
[Skip to Content Landing]
October 2, 1987

Reflux Esophagitis and the Water Bed

Author Affiliations

Stanford (Calif) University School of Medicine

Stanford (Calif) University School of Medicine

JAMA. 1987;258(13):1734. doi:10.1001/jama.1987.03400130048028

To the Editor.—  Wide reportage in the popular press of the letter by Kleinman and Plain1 has given the water bed industry heartburn. A representative of the National Waterbed Manufacturers Association, the industry's national trade association, asked me to review it.The correct P value2 is.051, not the reported "significant" P value of.035. This is only a careless mistake, but the letter is vague on many other important points.Were the cases that directed attention to water beds included in the study? This would be a more serious error. The minimal adjustment for it by deleting a single water bed user with reflux esophagitis increases the P value to.09. If only a subset of subjects with at least 2+ esophagitis was used, how was it chosen? The diagnosis of 2 + esophagitis is not clear-cut: "Erythema is difficult to distinguish from normal and friability depends on how hard you