Table 1.
Descriptive characteristics of the sample of children at 8-years-old
| Full Sample | Non-ADHD | ADHD | ||||||
|---|---|---|---|---|---|---|---|---|
| N | Mean (SD) | Range | N | Mean (SD) | N | Mean (SD) | T | |
| Age in years | 160 | 8.56 (0.31) | 7.91 – 9.33 | 74 | 8.54 (0.30) | 86 | 8.57 (0.31) | −0.62 |
| Socioeconomic Status (SES) | 160 | 63.91 (17.94) | 20 – 97 | 74 | 68.85 (15.92) | 86 | 59.65 (18.56) | 3.38† |
| WPPSI-III Full Scale IQ at 3–4 years old | 160 | 107.35 (13.41) | 80 – 144 | 74 | 112.11 (12.52) | 86 | 103.26 (12.85) | 4.40‡ |
| Working Memory Index (WMI) | 157 | 99.68 (13.99) | 65 – 135 | 73 | 105.04 (12.94) | 84 | 95.02 (13.25) | 4.79‡ |
| Spatial Span Averaged Scaled Score | 160 | 10.60 (2.95) | 2 – 18 | 74 | 11.61 (2.50) | 86 | 9.74 (3.04) | 4.27‡ |
| KSADS Inattentive Severity Score | 160 | 9.42 (6.57) | 0 – 18 | 74 | 3.15 (3.16) | 86 | 14.81 (2.90) | −24.20‡ |
| KSADS Hyperactive/Impulsive Severity Score | 160 | 8.20 (6.04) | 0 – 18 | 74 | 3.12 (3.36) | 86 | 12.57 (4.10) | −16.01‡ |
| WIAT-II Word Reading | 160 | 112.90 (10.80) | 65 – 131 | 74 | 115.51 (8.16) | 86 | 110.65 (12.24) | 2.99† |
| WIAT-II Reading Comprehension | 158 | 108.80 (12.95) | 65 – 150 | 74 | 112.68 (11.90) | 84 | 105.38 (12.93) | 3.69‡ |
| WIAT-II Pseudoword Decoding | 160 | 110.57 (12.67) | 75 – 130 | 74 | 113.24 (10.70) | 86 | 108.28 (13.79) | 2.56 |
| WIAT-II Numerical Operations | 159 | 108.88 (15.13) | 52 – 149 | 74 | 113.36 (13.23) | 85 | 104.98 (15.67) | 3.66‡ |
| WIAT-II Spelling | 158 | 114.15 (16.25) | 57 – 151 | 74 | 118.27 (14.74) | 84 | 110.52 (16.73) | 3.09† |
| NICHQ Classroom Academic Functioning | 126 | 8.67 (2.86) | 1 – 15 | 50 | 7.26 (2.28) | 72 | 9.79 (2.75) | −5.53‡ |
| NICHQ Classroom Behavioral Functioning | 126 | 14.72 (5.91) | 1 – 25 | 50 | 11.28 (4.58) | 72 | 17.31 (5.38) | −6.65‡ |
| Children’s Global Assessment Scale (CGAS) | 160 | 58.49 (16.96) | 30 – 92 | 74 | 73.73 (11.69) | 86 | 45.37 (6.67) | 18.44‡ |
| Percentages (N = 160) | Percentages (N = 74) | Percentages (N = 86) | X2 | |||||
| Gender (% males) | 75.6 | 70.3 | 80.2 | 2.14 | ||||
| Race | 11.97† | |||||||
| White/Caucasian (%) | 58.8 | 52.7 | 64.0 | |||||
| Black/African-American (%) | 10.6 | 5.4 | 15.1 | |||||
| Asian/Pacific Islander (%) | 12.5 | 20.3 | 5.8 | |||||
| Other/Mixed Race (%) | 18.1 | 21.6 | 15.1 | |||||
| Ethnicity | 1.23 | |||||||
| Non-Hispanic (%) | 70 | 74.3 | 66.3 | |||||
| Hispanic (%) | 30 | 25.7 | 33.7 | |||||
*
SD = Standard Deviation; KSADS = Kiddie-Schedule of Affective Disorders and Schizophrenia; WIAT-II = Wechsler Individual Achievement Test, Second Edition; NICHQ = National Institute of Children’s Healthcare Quality Vanderbilt Assessment Scale, Teacher Version
†
p < 0.01
‡
p<0.001