Exploratory Study into the Classification Agreement between Self-Reported Age of Menarche and Calculated Maturity Offset in Adolescent Girls: A Two-Year Follow-Up Study

Abstract

settingsOrder Article Reprints Open AccessArticle Exploratory Study into the Classification Agreement between Self-Reported Age of Menarche and Calculated Maturity Offset in Adolescent Girls: A Two-Year Follow-Up Study by Barry Gerber *ORCID andAnita E. PienaarORCID Physical Activity Sport and Recreation (PHASReC) in the Faculty of Health Science, Potchefstroom Campus, North-West University, Potchefstroom 2531, South Africa * Author to whom correspondence should be addressed. J. Funct. Morphol. Kinesiol. 2024, 9(3), 127; https://doi.org/10.3390/jfmk9030127 Submission received: 10 June 2024 / Revised: 11 July 2024 / Accepted: 16 July 2024 / Published: 19 July 2024 (This article belongs to the Section Physical Exercise for Health Promotion) Downloadkeyboard_arrow_down Browse Figure Review Reports Versions Notes Abstract Menarche is a significant pubertal event influencing girls' participation in physical activity. As menarche is a sensitive matter, a non-invasive substitute is needed to help classify girls' maturity status and provide physical literacy to them in this regard. The objective of this exploratory study was to investigate the classification agreement between self-reported age of menarche and calculated maturity offset in adolescent girls from South Africa by making use of various statistical methods. Fifty-eight girls, n = 13 pre- and n = 45 post-menarche (Status Quo method) aged 13.51 ± 3.51 years at baseline, were analyzed (2010-2012). Independent t-testing, cross-tabulation, Roc Curve statistics and logistic regression were used to analyze the classification agreement between markers. All four statistical methods revealed the potential to categorize different maturity groups through the maturity offset equation, although the accuracy declined with increased age. A realized power of 0.92 was found for the group in the first year of the study, with a gradual and significant decline over time. Cross-tabs showed a significant moderate predictive effectiveness (Chi-square = 0.042) during T1, closer to PHV (13.51 years) although also declining significantly with increased age (T2, 14.51 years) beyond PHV (Chi-square = 0.459). Although positive results were found, caution must be used when using maturity offset equations in different homogenic populations due to their unique growth characteristics.