Follow-up at mid-school age (9-13 years) of children assessed for autism spectrum disorder before the age of four.

Background: Studies of diagnosis and outcome in mid-school age children (9-13 years) referred early in life for a suspected autism spectrum disorder (ASD) are scarce.

Aims: This study aimed to describe outcome, developmental change and the stability of the early diagnosis in mid-school age.

Methods: Children consecutively referred to a specialized autism unit at a regional psychiatric diagnostic centre in Denmark before the age of 4 were contacted in mid-school age (9-13 years).