Validity of self-reported measurement of pubertal development in 12-year-old children

BACKGROUND: The Tanner scale is the reference for assessing pubertal development. In epidemiologic studies, self- or parent-assessments are frequently used, though their accuracy is not regularly discussed. We compared this measurement with clinical evaluations (as gold standard) among 12-year-old children in the general French population and examined factors explaining discrepancies. METHODS: Within the PELAGIE mother-child cohort conducted in Brittany (France), clinical examinations of 498 children were performed by trained medical staff to assess pubertal development (breasts, gonads, and pubic hair) using Tanner stages. Children and parents completed assessments within the previous days, and had the option to declare two stages in case of hesitation. Agreement between the self- and parent reports and the clinical assessments was evaluated using weighted kappa, intraclass correlation coefficient (ICC), and Correspondence Analysis. We used robust Poisson regressions to examine potential correlates (determined a priori) of discordant assessments. RESULTS: Among girls, 68.1% correctly assessed breast stage compared with clinical assessment (ICC=0.72), though overestimation was common (31.1%). Accuracy for pubic hair was 68.6% in girls (ICC=0.79) and 60.3% in boys (ICC=0.73). Only 38.3% of boys accurately reported their gonadal stage (ICC=0.38), often underestimating (68.1%). Self-reporting of hesitant responses improved concordance with clinical assessments. Pubertal and morphological indicators, such as voice change, contributed to reducing discrepancies in self-assessment. Parents' reports showed similar trends to children's, but with frequent non-responses. CONCLUSION: The accuracy of self-assessment of pubertal stage in our French population of 12-year-olds was generally good, supporting its use as a reliable tool, particularly among girls. For gonadal development, a potential systematic and informative errors were present, with underestimation. The use of reporting hesitant responses in children appears to be a promising approach while the added value of parental assessment remains limited.