Table 3.

Summary of examiner ratings, coded behavior, and parent concerns for ADHD-risk and low-risk groups at 12, 18, and 24 months of age.

Variable	12 months		18 months		24 months
	ADHD-risk (n = 43)	Low-risk (n = 40)	ADHD-risk (n = 43)	Low-risk (n = 40)	ADHD-risk (n = 43)	Low-risk (n = 40)
Examiner Ratings a
Attention, mean (SD)	2.5 (0.9)*	2.1 (1.0)*	3.0 (1.0)	2.7 (0.9)	3.2 (1.1)*	2.4 (1.0)*
Activity, mean (SD)	3.0 (1.1)*	2.4 (1.1)*	3.3 (1.1)	2.9 (1.1)	3.3 (1.2)*	2.6 (1.2)*
Impulsivity, mean (SD)	2.7 (1.0)*	1.8 (0.8)*	3.2 (1.0)*	2.7 (1.1)*	3.4 (1.0)*	2.8 (1.3)*
Coded Behavior b
Inattention
Mean (SD)	2.5 (2.6)	2.4 (1.8)	4.3 (2.9)	3.2 (2.5)	3.2 (2.4)	2.3 (2.1)
Median [Q1-Q3]	2 [0 - 4]	2 [1 - 3]	5 [2 - 6]	3 [2 - 6]	3 [1 - 5]	2 [0 - 4]
Out of Seat
Mean (SD)	1.6 (2.6)*	0.6 (1.1)*	3.0 (3.2)*	1.7 (1.9)*	2.3 (2.9)	1.4 (1.8)
Median [Q1-Q3]	1 [0 - 2]	0 [0 - 1]	3 [0 - 5]	1 [0 - 3]	1 [0 - 3.5]	1 [0 - 2]
Grab
Mean (SD)	4.1 (2.7)*	2.7 (2.3)*	4.3 (3.0)*	2.8 (3.0)*	2.6 (2.5)	1.9 (2.1)
Median [Q1-Q3]	4 [2 - 6]	2 [1 - 4]	4 [1 - 6]	3 [1 - 4]	2 [1 - 3.5]	1.5 [0 - 3]
Parent Concernsc, n (%)	7 (18.9%)*	2 (5.1%)*	14 (34.2%)*	1 (2.6%)*	12 (32.4%)*	4 (11.1%)*

Data are missing for:

^an = 6 ADHD-risk and 1 low-risk at 12 months, n = 2 ADHD-risk and 2 low-risk at 18 months, and n = 6 ADHD-risk and 4 low-risk at 24 months;

^bn = 6 ADHD-risk and 1 low-risk at 12 months, n = 2 ADHD-risk and 2 low-risk at 18 months, and n = 7 ADHD-risk and 4 low-risk at 24 months;

^cn = 6 ADHD-risk and 1 low-risk at 12 months, n = 2 ADHD-risk and 2 low-risk at 18 months, and n = 6 ADHD-risk and 4 low-risk at 24 months;

^*p < .05 at specified age for the linear contrast estimating visit-specific differences between the ADHD-risk and low-risk groups from mixed-effect linear regression models for examiner ratings, mixed-effect negative binomial regression models for behavior codes, and mixed-effect logistic regression model for parent concerns.