Self-assessment of pubertal Tanner stage by realistic colour images in representative Chinese obese and non-obese children and adolescents

Aim: This investigation aims to evaluate the validity of self-assessment of pubertal Tanner stage in representative Chinese children and adolescents. Methods: The study is a nationally representative cross-sectional survey in eight research sites in the large project entitled 'China Puberty Research Collaboration'. Weight, height, self-assessed pubertal Tanner stage and physical examination of pubic hair in each gender, breast development in girls and genital development in boys from were analysed. Realistic colour images of pubertal rating were used as self-assessment of pubertal stage. Results: A large proportion of subjects aged 7.9-18.9 years old were capable of identifying their own pubertal Tanner stage accurately or close to the rater's assessments. Obese group tends to overestimate their pubertal development compared to non-obese peers, except for genital assessment in boys. The k values for non-obese and obese girls were 0.619 (p < 0.0001) and 0.527 (p < 0.0001), respectively, while the k values for non-obese and obese boys were 0.503 (p < 0.0001) and 0.352 (p < 0.0001). Conclusions: Self-assessment of the pubertal stage by using realistic colour images could be a better alternative assessment tool for large epidemiological puberty research compared with Tanner's original black and white pictures.