- 作者：Krista Yorita Christensen ; Mildred Maisonet ; Carol Rubin ; W. Dana Fl ; ers ; Carolyn Drews-Botsch ; Celia Dominguez ; Michael A. McGeehin ; Michele Marcus
- 关键词：ALSPAC ; Maximum Likelihood Estimation ; Puberty
- 刊名：Annals of Epidemiology
- 出版年：2010
- 出版时间：May 2010
- 年：2010
- 卷：20
- 期：5
- 页码：405-408
- 全文大小：88 K
Purpose
The timing of breast and pubic hair development in girls are related, but the degree of correlation has not been well characterized. Periodic observations also are complicated by interval censoring.Methods
Data used were from the Avon Longitudinal Study of Parents and Children. Mean age at entry into breast and pubic hair development was determined by the use of parametric survival analysis. The bivariate normal cumulative distribution function was evaluated over the region containing the paired event times; the likelihood was maximized with respect to the correlation coefficient ρ.
Results
Among 3938 participants, estimated mean ages at entry into Tanner stage 2 for breast and pubic hair development were 10.19 and 10.95, respectively. The likelihood was maximized at ρ = 0.503 to 0.506. This value remained relatively constant among subgroups, although some heterogeneity was observed by maternal and child body mass index and birth order.
Conclusions
The timing of breast and of pubic hair development is moderately correlated and remain so when it is stratified by characteristics associated with puberty.