Table 2.
Correlations Between Parent- and Child-Reported Strengths and Difficulties Questionnaire Scores at Age 11 Years in the Danish National Birth Cohort (n = 40,934), 1996–2002
| Score | Parent Report | Child Report | Pearson Correlation Coefficient | Cronbach’s α (Reliability) | κ Coefficient | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Median (IQR) | Cutoff to Indicate Behavioral Difficulties | Children With Behavioral Difficulties | Median (IQR) | Cutoff to Indicate Behavioral Difficulties | Children With Behavioral Difficulties | ||||||
| No. | % | No. | % | ||||||||
| Composite score | |||||||||||
| SDQ total difficultiesa | 4 (2–8) | 17 | 1,183 | 2.9 | 6 (3–10) | 20 | 817 | 2.0 | 0.58 | 0.73 | 0.30 |
| Internalizingb | 2 (1–4) | 8 | 2,116 | 5.2 | 3 (1–5) | 9 | 2,232 | 5.5 | 0.49 | 0.66 | 0.29 |
| Externalizingc | 2 (1–4) | 8 | 3,029 | 7.4 | 3 (1–6) | 9 | 3,014 | 7.4 | 0.59 | 0.74 | 0.38 |
| SDQ subdomainsd | |||||||||||
| Emotional symptoms | 1 (0–3) | 5 | 3,806 | 9.3 | 1 (0–3) | 7 | 958 | 2.3 | 0.48 | 0.65 | 0.17 |
| Conduct problems | 0 (0–1) | 4 | 1,312 | 3.2 | 1 (0–2) | 5 | 933 | 2.3 | 0.46 | 0.63 | 0.24 |
| Hyperactivity | 2 (0–3) | 7 | 1,792 | 4.4 | 2 (1–4) | 7 | 2,088 | 5.1 | 0.57 | 0.72 | 0.38 |
| Peer problems | 0 (0–1) | 4 | 1,852 | 4.5 | 1 (0–2) | 6 | 782 | 1.9 | 0.40 | 0.57 | 0.20 |
| Prosocial behavior | 7 (6–8) | 4 | 2,250 | 5.5 | 8 (7–9) | 4 | 1,364 | 3.3 | 0.34 | 0.51 | 0.15 |
Abbreviations: IQR, interquartile range; SDQ, Strengths and Difficulties Questionnaire.
a The SDQ total difficulties score ranges from 0 to 40, and is the sum of the emotional (0–10), conduct (0–10), hyperactivity (0–10), and peer problems (0–10) scales.
b The internalizing score ranges from 0 to 20 and is the sum of the emotional and peer problems scales. Cutoff was defined as 95th percentile.
c The externalizing score ranges from 0 to 20 and is the sum of the conduct and hyperactivity scales. Cutoff was defined as 95th percentile.
d Higher scores on the first 4 subscales reflect difficulties, whereas higher scores on the prosocial subscale (0–10) reflect strengths.