Table 4. Developmental Characteristics of Children With Down Syndrome Aged 2–11 Years Who Were Enrolled and Screened for Autism Spectrum Disorders.

Characteristic	Screen-Positive Weighted Percent (95% CI)	Screen-Negative Weighted Percent (95% CI)	p
Autism spectrum disorder	35.6 (23.2–50.2)	6.4 (1.9–20.2)	.018
Diagnosis			<.001
Autistic disorder	13.3 (6.3–26.3)	0.0 (0.0–10.6)
Pervasive developmental disorder—not otherwise specified	22.2 (12.6–36.4)	6.4 (1.9–20.2)
Severity of cognitive impairmenta			.001
Mild	28.5 (13.2–43.9)	63.3 (45.6–81.0)
Moderate	31.4 (15.6–47.2)	20.0 (0.05–34.7)
Severe	22.9 (8.6–37.1)	16.7 (3.0–30.3)
Profound	17.1 (4.3–20.0)	0.0 (0.0–0.0)
Standardized testing
Developmental quotienta	41.0 (36.1–45.9)	52.1 (48.2–56.0)	.001
Vineland communication standard scoreb	45.2 (37.6–52.8)	43.8 (35.8–51.9)	.80
Vineland socialization standard scoreb	48.2 (40.3–56.1)	45.5 (37.2–53.8)	.63
Vineland daily living standard scoreb	46.6 (39.1–54.2)	42.9 (33.9–51.8)	.51
Vineland motor skills standard scorec	67.7 (59.8–75.7)	74.0 (68.8–79.2)	.20

^aMissing data for 2 screen-negative (SN) and 10 screen-positive (SP) children.

^bMean = 100; missing data for 6 SN and 12 SP children.

^cMean = 100; missing data for 10 SN and 10 SP children.