The mode ages of women with cervical dysplasia

To resolve the discrepancy that women seem to have Papanicolaou smears with dysplasia at younger ages than the reported mean ages.

Every other Papanicolaou smear diagnosed during a 5-year period at our institution was reviewed. There were 1947 cases with dysplasia or carcinoma. Dysplasia was defined as a lesion of disordered squamous epithelial differentiation and was graded by standard criteria. The mean, median, and mode ages of the women were determined by diagnosis. Normal (symmetrical) distribution was tested for each population, and significant differences were sought by diagnosis.

Normal distribution was rejected for the ages of women with all grades of dysplasia and carcinoma in situ, but not for the ages of women with carcinoma.

Because the ages of women with dysplasia are not distributed normally, but are asymmetrically skewed to younger women, we suggest that the mode better describes the central tendency for ages of women with dysplasia. The difference between the mean and mode ages of these women explains the apparent discrepancy between the reported mean ages and our clinical impression. Appropriate descriptive statistics like these help the clinician evaluate individual patients in the true context of the disease.