Physician accuracy in diagnosing colorectal polyps.

Since the medical management of persons with adenomatous colorectal polyps differs from that of those with hyperplastic polyps, accuracy of diagnosis is essential. Although many physicians have grown confident that their skills of visual diagnosis are adequate, few data exist to support this confidence. In order to examine the accuracy of physicians' judgments regarding colorectal polyp histology, the visual diagnosis of physicians experienced in endoscopy was compared with the histologic report. Eighty-one polyps were discovered by flexible sigmoidoscopy among 718 participants in a colon cancer screening program. Eighty percent of all polyps were detected accurately. The diagnostic sensitivity of detecting adenomas was 69 percent, while specificity (accurate diagnosis of hyperplastic polyps) was 86 percent, and there were an additional eight false negative and eight false positive diagnoses. Further analyses revealed that there are individual patterns of diagnostic mistakes made by physicians and that mistakes frequently are related to polyp size. These findings are particularly important in light of the expanding numbers of relatively inexperienced primary care providers performing flexible sigmoidoscopy whose diagnoses may be strongly dependent on polyp size.