Two-stage window screening and development trajectories in early identification of autism spectrum disorder among Han Chinese children.

The growth trajectory showed that children's language development began to increase at 18 months, and peaked at 36 months. On the other hand, social development showed steady growth from 18 to 66 months. The increase in the trajectory of children's language development prior to age three, when compared with other developmental dimensions, may increase the difficulty of diagnosing ASD. The two-stage window screening method can be used in settings where the screening sample is large, such as in community or primary care settings, and has been found to be time- and cost-efficient. Better understanding of children's developmental trajectory can enhance detection and intervention for ASD.