Report | ASD, n | Age (years) at baseline | Length of follow-up (occasions) | Cognitive ability level at baseline | Summary of findings |
---|---|---|---|---|---|
421 | 3.32 ± 0.75 | Four assessments: baseline, 6 and 12 months post-baseline, and age 6 years | Merrill-Palmer-Revised Developmental Index (full-scale IQ): 57.23 ± 26.20 | Three classes of ABC trajectory: lower/worsening, moderate/stable, and higher/improving | |
Anderson et al. [26] | 144 | 2.46 ± 0.39 | Six assessments at approximate ages of 2, 3, 5, 9, 18, and 21 years (plus parent report at 10 and 13 years) (not all time points used in all publications) | Non-verbal IQ: 62.4 ± 17.36 | Outcome was Vineland socialization age equivalent. Two classes were observed for both groups. Autism—low and flat, and moderate with age-appropriate growth. PDD—moderate with faster than expected growth, and low with moderate growth |
Bal et al. [32] | Autism: 93 PDD: 51 | Autism: 2.43 ± 0.42 PDD: 2.43 ± 0.47 | Mullen Scales of Early Learning Non-verbal mental age: 1.62 ± 0.56 years | Two classes of daily living skills age equivalents trajectory: high and low. While both gained skills over time, the low group gained at a slower rate. | |
Baghdadli et al. [28] | 152 | 4.9 ± 1.3 | Three assessments at approximately 5, 8, and 15 years | Did not use standard assessments. “cognition related to object (months)”: 22.4 ± 11.9; “Cognition related to person (months)”: 19.2 ± 10.8 | Across the subdomains of adaptive behavior, two patterns of development in age equivalents were observed: one with little growth across the time points and the other with substantial but less-than-expected growth. |
Current study | 105 | 4.24 ± 1.30 | Follow-up at 6-month intervals prior to the third birthday; annual follow-ups until 3 years of study participation | Full-scale developmental quotient: 49.88 ± 16.83 | Two classes of ABC trajectory: low/decreasing, moderate/stable |