Table 2.
Regression Models of Attention-Deficit/Hyperactivity Disorder (ADHD) Symptoms for Relative Age
| ADHD symptoms | Age, y | Rater | Relative age |
[95% CI] | p | n |
|---|---|---|---|---|---|---|
| Coefficient | ||||||
| Conners' | 8 | Parent | 2.01 | [1.30 to 2.71] | <0.001 | 4,162 |
| 12 | Parent | 2.23 | [1.53 to 2.93] | <0.001 | 3,642 | |
| 14 | Parent | 1.94 | [0.99 to 2.88] | <0.001 | 1,850 | |
| Self | 0.76 | [−0.09 to 1.61] | 0.078 | 1,831 | ||
| 16 | Parent | 1.13 | [0.50 to 1.77] | <0.001 | 3,141 | |
| 21 | Parent | 1.40 | [0.81 to 1.99] | <0.001 | 3,422 | |
| SDQ | 7 | Parent | 0.42 | [0.25 to 0.58] | <0.001 | 4,685 |
| Teacher | 0.66 | [0.45 to 0.86] | <0.001 | 3,751 | ||
| 9 | Parent | 0.34 | [0.09 to 0.59] | 0.008 | 1,930 | |
| Teacher | 0.60 | [0.33 to 0.87] | <0.001 | 1,697 | ||
| 12 | Parent | 0.46 | [0.29 to 0.63] | <0.001 | 3,638 | |
| Teacher | 0.19 | [−0.01 to 0.40] | 0.063 | 3,081 | ||
| Self | 0.33 | [0.16 to 0.50] | <0.001 | 3,626 | ||
| 16 | Parent | 0.13 | [−0.03 to 0.29] | 0.125 | 3,135 | |
| Self | 0.11 | [−0.07 to 0.29] | 0.217 | 3,129 | ||
| 21 | Parent | 0.18 | [0.02 to 0.33] | 0.025 | 3,413 | |
| Self | 0.20 | [0.03 to 0.38] | 0.023 | 3,009 | ||
| GCSE score, mean [SD] | ||||||
| English | −0.11 | [−0.21 to −0.02] | 0.020 | 4,039 | ||
| Mathematics | −0.01 | [−0.12 to 0.10] | 0.830 | 4,020 | ||
Note: Conners' = Revised Conners' ADHD symptoms Parent Rating Subscale and Self-Report Rating Subscale; GCSE = General Certificate of Secondary Education; n = number of observations; SDQ = Strengths and Difficulties Questionnaire.