an overall trendgold
An overall trend is that for subgroups diagnosed with autism early at preschool age (i.e., Classes 1 and 2), other conditions tended to be diagnosed concurrently with or after the autism diagnosis, whereas for subgroups with autism initially diagnosed in middle childhood through adolescence (i.e., Classes 3 and 4), other conditions were more often diagnosed concurrently with or before the autism diagnosis.