The retrospective cross-sectional analysis by Dunn et al1 in a recent issue of the Archives demonstrates the difficulties confronted when performing an analysis of data that were collected years earlier and not intended to answer the question at hand. For reasons of study design, it is difficult to determine the significance of the analytical results of this study. Because the examination survey by Dunn et al subjectively assessed skin surface appearance only, it is also difficult to compare the results with those of previous studies that have objectively evaluated non—sun-exposed site skin thickness.
The study of 3835 postmenopausal women participating in the First National Health and Nutrition Examination Survey examined the relationship of estrogen replacement therapy and surface skin appearance. Between 1971 and 1974, these women underwent complete skin examinations performed by dermatology residents. As part of this examination, residents noted the presence of skin atrophy, senile dryness, and
Whitmore SE. Estrogen, Skin Aging, and Study Design. Arch Dermatol. 1997;133(11):1460-1461. doi:10.1001/archderm.1997.03890470140028