Table 1.

Demographics according to Ever ASD vs Never ASD diagnoses

	Ever ASD n=48	Never ASD n=30
Number male (%)	38 (79.16)	22 (73.33)
Chronological age (Baseline)	17.25 (5.58)	17.00 (5.82)
Chronological age at (Final)	35.04 (7.01)	31.70 (7.09)
Number of observations	6.79 (4.72)	5.43 (4.25)
Mullen receptive language age equivalent* (Baseline)	12.69 (7.39)	15.10 (7.50)
Mullen expressive language age equivalent* (Baseline)	12.02 (6.20)	14.20 (6.01)
Mullen verbal IQ* (Baseline)	66.07 (24.64)	79.00 (28.66)
Mullen nonverbal IQ* (Baseline)	92.96 (20.44)	94.97 (27.56)
ADOS Social Affect subtotal (Baseline)	11.42 (4.89)	5.60 (4.01)
ADOS RRB subtotal (Baseline)	3.54 (1.72)	1.77 (1.41)
ADOS Algorithm total (Baseline)	14.96 (5.88)	7.37 (4.22)
Clinician diagnostic certainty rating (Baseline)	10.56 (4.63)	4.12 (1.05)
ADI-R subtotals (at approximately 30 months)	n=47	n=25
Reciprocal Social Interaction	12.23 (6.48)	6.16 (4.70)
Verbal Communication	8.94 (6.11)	4.60 (3.44)
Nonverbal Communication	8.17 (4.52)	5.48 (4.24)
Restricted and Repetitive Interests	4.06 (2.64)	1.68 (1.63)

Note: Values above are averages, with standard deviations in parentheses, unless otherwise indicated.

T1 = Time 1; ADOS=Autism Diagnostic Observation Schedule; ADI-R=Autism Diagnostic Interview-Revised (for 47 “ever” ASD; 25 “never ASD”).