TABLE 3.
Risk of RDa Associated with Gender, Separately by ADHD Status
| N | Number of RD cases by age 19 | Cumulative incidence by age 19, % (95%CI) | Unadjusted HRb (95% CI), P-value | Adjusted HRc (95% CI), P-value | |
|---|---|---|---|---|---|
| ADHD | |||||
| Boys | 284 | 137 | 51.0 (44.5–56.6) | 1.10 (0.78–1.55), 0.58 | 1.04 (0.73–1.50), 0.83 |
| Girls | 95 | 43 | 46.7 (35.5–56.0) | 1.00 | 1.00 |
| Non-ADHD | |||||
| Boys | 2666 | 332 | 14.5 (13.0–15.9) | 1.97 (1.64–2.36),<0.001 | 2.03 (1.67–2.45), <0.001 |
| Girls | 2654 | 176 | 7.7 (6.6–8.8) | 1.00 | 1.00 |
HR, hazard ratio for boys vs. girls.
a
RD, reading disability as determined by any of the three formulas.
b,c
There is a statistically significant difference between the HR (for boys vs. girls) among ADHD children and that among non-ADHD children (P = 0.003 in the unadjusted model and P = 0.001 in the adjusted model).
c
Adjusted for children’s race (white v. non-white), mother’s educational level (four categories) and mother’s age at birth of child.