Supplementary Material for: Early Mental Trajectories Predict Different Cognitive Levels at School Age in Very Preterm Children

Introduction: Early identification of preterm children at high risk of intellectual disability (intelligence quotient [IQ] Methods: A multicenter study recruited preterm infants born at Results: Among the 1,680 children enrolled, three mental trajectories were identified: high-stable (59.7%), high-declining (35.3%), and low-declining (5.0%), in which the borderline-intelligence/intellectual-disability rate was 14.1%/1.5%, 36.1%/13.7%, and 10.7%/82.1%, respectively. Compared with children with normal intelligence, the low-declining trajectory had 37.7-fold higher odds (95% confidence interval [CI], 26.3–48.1) for intellectual disability, and the high-declining trajectory had 4.4-fold higher odds (95% CI, 3.1–6.1) for borderline intelligence. Compared to the models with risk factors alone (AIC 1,791.2), the models that included both risk factors and trajectory groups had better overall performance (AIC 1,419.8) and increased prediction power for intelligence outcomes: low-declining trajectory for intellectual disability (AUROC increased from 0.81 to 0.92) and high-declining trajectory for borderline intelligence (AUROC increased from 0.68 to 0.75). Conclusions: Early-life mental trajectories help identify preterm children at risk of intellectual disability and borderline intelligence, respectively, at school age for timely intervention.