Predicting developmental status from 12 to 24 months in infants at risk for Autism Spectrum Disorder: a preliminary report

Abstract

The study examined whether performance profiles on individual items of the Toddler Module of the Autism Diagnostic Observation Schedule at 12 months are associated with developmental status at 24 months in infants at high and low risk for developing Autism Spectrum Disorder (ASD). A nonparametric decision-tree learning algorithm identified sets of 12-month predictors of developmental status at 24 months. Results suggest that identification of infants who are likely to exhibit symptoms of ASD at 24 months is complicated by variable patterns of symptom emergence. Fine-grained analyses linking specific profiles of strengths and deficits with specific patterns of symptom emergence will be necessary for further refinement of screening and diagnostic instruments for ASD in infancy.

Fig. 1

Histogram illustrating the proportion of infants receiving total algorithm scores from 0 to 25 on ADOS-T at 12 months in infants with typical (TYP), atypical (ATYP), and ASD developmental status at 24 months. The vertical lines depict their respective group means

Fig. 2

TYP versus non-TYP classification tree. Numbers at each junction (0–3) represent the actual ADOS-T scores attained on a given item by each subgroup. The numbers on each branch represent the percentage of the total subjects that fall into each region of the tree. Under each leaf is the percentage of subjects within the leaf that are TYP or non-TYP. For instance, for the leaf defined by scores of 2 or higher item B12, 50 % of total subjects fell into that leaf, and 79 % of subjects in the leaf were non-TYP. Selected variables: showing (B12), overactivity (E1), and initiates joint attention (B13)

Fig. 3

ASD versus non-ASD classification tree. Numbers at each junction (0–3) represent the actual ADOS-T scores attained on a given item by each subgroup. The numbers on each branch represent the percentage of the total subjects that fall into that region of the tree. Under each leaf is the percentage of subjects within the leaf that are ASD or non-ASD. For instance, for the leaf defined by scores of 2 or higher on item B17, 7.1 % of total subjects fell into that leaf, and 83 % of subjects in the leaf were ASD. Selected variables: level of engagement (B17), amount of requesting (B10), imitation (C3), fussiness (E2), showing (B12), intonation (A3), and gestures (A8). Leaves that contained infants with a CBE of ASD at 24 months according to this tree are highlighted with colored circles: ASD₁: severe, stable symptoms; ASD₂, ASD₃: increasing symptoms, ASD₄: decreasing symptoms

Fig. 4

ADOS-T total algorithm scores at 12–24 months for the four ASD subgroups

Fig. 5

Mullen domain DQ scores at 12 and 24 months for the four ASD subgroups