Table 3. Difference (95% confidence interval) in mean AH4 score according to father's age at respondent's birth.
| N | Adjusted for age at IQ measurement | Adjusted for age and father's education1 | Adjusted for age and father's SES1 | Adjusted for age and total number of siblings | Adjusted for age and number of older siblings | Multiply adjusted2 | |
| All respondents (N = 772) | |||||||
| <25 | 144 | −2.15 (−4.17, −0.14) | −1.96 (−3.91, −0.01) | −1.15 (−3.10, 0.80) | −2.25 (−4.24, −0.26) | −3.08 (−5.07, −1.08) | −2.11 (−4.04, −0.17) |
| 25–29 | 254 | 0.00 (ref) | 0.00 (ref) | 0.00 (ref) | 0.00 (ref) | 0.00 (ref) | 0.00 (ref) |
| 30–34 | 217 | 1.98 (0.19, 3.77) | 1.47 (−0.26, 3.21) | 1.25 (−0.48, 2.97) | 2.23 (0.47, 4.00) | 2.74 (0.97, 4.50) | 1.74 (0.03, 3.45) |
| 35+ | 157 | −0.94 (−2.90, 1.02) | −1.00 (−2.90, 0.90) | −1.09 (−2.97, 0.80) | 0.31 (−1.69, 2.31) | 1.65 (−0.45, 3.75) | 0.88 (−1.14, 2.89) |
| P3 | <0.001 | 0.01 | 0.05 | <0.001 | <0.001 | 0.004 | |
1
Adjustment for mother's education and SES had a similar or weaker impact on these associations; 2Adjusted for age, father's education, father's SES, and number of older siblings; 3p for heterogeneity based on likelihood ratio test.