Abstract: Background：The disturbance coefficient(DC) is the main technical parameter of noninvasive brain edema dynamic monitoring instruments, and there is no normal reference value for children and adolescents at home abroad. Objective：To establish the reference intervals of DC for children and adolescents aged 116 years. Design：Multicenter prospective crosssectional survey. Methods：From March 2020 to March 2023, children and adolescents aged 116 years without craniocerebral injury were recruited from 6 hospitals 2 kindergarten and primary schools in Chongqing, Sichuan and Shenzhen. The noninvasive brain edema dynamic monitor was used for continuous monitoring for 15 minutes, and the monitoring average was taken as the final DC value of the subjects. Generalized Additive Models for Location, Scale, and Shape (GAMLSS) were used to draw P1, P5, P10, P25, P50, P75, P90, P95, P99 percentile values and percentile curves for disturbance coefficients of different ages. Independent sample ttest was used to analyze the difference of DC between boys and girls, and analysis of variance was used to calculate the DC mean value in different age groups and the difference of DC in different age groups. The changes of DC with age, weight and head circumference were explored by drawing scatter plots and Loess local weighted nonparametric regression curves. Main outcome measures：Disturbance coefficient. Results：A total of 1 247 children and adolescents with no cranial injuries were included in the study, including 787 males (63.1%) and 460 females. The observed fitted percentile curves of disturbance coefficients for children and adolescents of different ages showed that the level of disturbance coefficients gradually increased with age, and the growth of disturbance coefficient curves slowed down and eventually stopped after 5 years of age. In the overall population, there was no significant difference in DC levels between males and females (P>0.05), and there was no significant difference in DC among children and adolescents of different ages and genders. Correlation analysis showed that when age＜5 years old, body weight<18.0 kg and head circumference<51.0 cm, DC was significantly positively correlated with age, body weight and head circumference (r=0.663, 0.454 and 0.474, respectively). On the contrary, when age≥5 years old, body weight≥18.0 kg and head circumference≥51.0 cm, DC did not change significantly and gradually stabilized at 107. Conclusions：The study constructed the percentile curve of DC in children and adolescents aged 1 to 16 years old. When the age was ＜5 years old, the DC increased with age, and when the age was ≥5 years old, the DC gradually stabilized at 107.

Key words: Children and adolescents, Disturbance coefficient, Reference value, Percentile curve, GAMLSS