Differences Between Nurse's Estimates TABLE | and Chronologic Age (by Sex and Exposure Group) Sex Group | Group 2 Male — .803 —.776 Female +.280 +.163 Group 3 Group 4 Total —1.09) —.182 —.701 +.035 +.183 +.165 Mean differences in age Number of cases Male 122 98 1190 121 45] . Female 232 208 227 186 853 The various tests were performed on elements of this sample, which com- prised hundreds of consecutive subjects '. who were examined during a period of several months. Estimate of age. One nurse, by a simple inspection of the subjects as they entered the clinic, recorded her estimate of each subject's age for comparison with actual chronologic age (table 1). Skin retractility, skin fold size, and skin looseness. These estimates were in most instances made by the same nurse, who used a simple multipurpose spring pincer-caliper designed by one of the authors (R. A. Conard). This instrument had previously been used in studies of aging on a group of Marshall Island natives exposed to fallout from a Bikini bomb test in 1954.78 The device is illustrated in figure II. Observations were made on 609 patients—their ages, sex, and exposure-group distribution are shown in table 2. The skin retractility test simply measures the time required for a standard “pinch” to retract. Skin at the base of the right thumb, just lateral to the anatomic snuffbox, was caught in a l-cm. opening of the pincer for a period of one minute. The time in seconds required for the skin to retract fully after release of the pincer was recordec GERIATRICS, JANUARY 1961 The skin fold under the chin was measured for thickness. The patient sat erect, the pincer was opened to 2 cm., and the two hands of the pincer were fitted firmly to the undersurface of the mandible. The pincer was allowed to close, and the length of the skin fold caught in the pincer was recorded from the calibrations on the side of the pincer arms. In the studies on the Marshallese people,? skin retractility was measured several centimeters above the knuckles on the back of the hands. Skin fold measurements were done at the junction of the neck and chin; graying of the hair was measured on a 0-4-+ scale. FIG. 1. Multipurpose spring pincer-caliper used for skin retractility, skin fold size, and skin looseness tests. 29