Multi-method confirmatory factor analyses of puberty in early adolescent girls
Authors: Byrne Michelle L , Chavez Samantha , Vijayakumar Nandita , Cheng Theresa W , Flournoy John Coleman , Barendse Marjolein , Shirtcliff Elizabeth A , Allen Nicholas B. , Pfeifer Jennifer H 
Published: July 2019

Abstract (full):Correctly measuring and operationalizing pubertal processes during development is important for capturing variation in both normative development and trajectories associated with adverse outcomes. The aim of the current study was to understand how this variance may be captured by different pubertal processes (adrenarche and gonadarche) and how multiple methods may contribute to variance (and how they are correlated). The study explored multi-method cross-sectional pubertal data, including self-reported physical characteristics from the Pubertal Development Scale (PDS) and Morris &amp; Udry line drawings, and levels of hormones dehydroepiandrosterone (DHEA), testosterone (T), and estradiol (E2) in saliva and hair, from a cohort of 174 early adolescent girls aged 10-13 years. Authors developed a theory-driven structural equation modelling framework of puberty for girls that includes multiple measures of puberty and considers both processes of adrenarche and gonadarche. Self-reported puberty and hormone levels from saliva and hair can estimate an overall pubertal process as well as each process of adrenarche and gonadarche. The self-reported PDS item on height growth had the lowest standardized loading of the self-report items. In full models with all measures, the more parsimonious one-factor model was not a significantly worse fit than the two-factor model. The shared variance between the hormonal latent puberty factor and the self-reported latent puberty factor was 32%. This suggests fairly good reliability between hormones and self-report puberty data but also suggests that measuring puberty via hormones and via self-report questionnaires is not entirely redundant, and models of puberty require collecting both. Exploratory analyses showed 34%, 48%, and 52% shared variance between chronological age and the adrenarcheal, gonadarcheal, and overall pubertal factors, respectively, suggesting that there is additional variance in these pubertal processes that is not explained by age alone. When controlling for age, the adrenarcheal and gonadarcheal factors were still strongly associated (90% shared variance), suggesting that these factors are correlated when calculated as pubertal timing (i.e., stage compared to same-age peers), as well. Finally, correlations with age were higher when using the latent factors, whether for self-report questionnaire data alone, or for hormones, and correlations were highest when using all available self-report and biological measures. Abstract (short):This structural equation modelling study explored how variance in pubertal development is captured by different processes (adrenarche and gonadarche) and methods, using cross-sectional pubertal data from a cohort of 174 early adolescent girls aged 10-13 years. Self-reported puberty and hormone levels from saliva and hair can estimate an overall pubertal process as well as each process of adrenarche and gonadarche. The self-reported PDS item on height growth had the lowest standardized loading of the self-report items. Hormonal and self-reported latent puberty factors had 32% shared variance, suggesting that research should collect both. There was 34%, 48%, and 52% shared variance between chronological age and the adrenarcheal, gonadarcheal, and pubertal factors, respectively, suggesting these processes are not explained by age alone.