Analysis of bone age data from national cooperative growth study substudy VII.

National Cooperative Growth Study substudy VII was conducted 1) to compare standardized hand-wrist and knee bone age determinations in pubertal children treated with growth hormone (GH); 2) to compare local determinations of bone ages with centrally determined bone ages; 3) to relate the response to GH therapy to the bone age determinations; and 4) to ascertain the predictive value of each type of bone age determination. Eligible subjects were those in the National Cooperative Growth Study who were at Tanner pubertal stage 2 or greater for breasts (girls) or genitals (boys). Radiographs of the hand-wrist were taken annually, and radiographs of the knee were taken at the beginning and the end of the study. Separate bone age determinations were made from these radiographs. A combined hand-wrist and knee bone age determination also was derived. There were 990 patients in the study; in 925 (677 boys), there were both hand-wrist and knee bone age determinations from the baseline pubertal radiographs. There was only one radiographic assessment in 496 patients, two in 205 patients, and three to eight in the remaining patients. The strongest correlation was between the hand-wrist bone age and the hand-wrist plus knee bone age (r =.995). Also strongly correlated were knee with hand-wrist (r =.872) and knee with hand-wrist plus knee (r =.914). For none of these bone age methods was any statistically significant difference found between the methods. The locally determined bone ages correlated strongly with the centrally determined bone ages for knee (r =.850), hand-wrist (r =.928), and hand-wrist plus knee (r =.930); however, the locally determined knee and hand-wrist values were less (by approximately 0.3 year) than the centrally determined values. These differences, however, do not appear to be clinically significant.