Birth weight and genetic risk of ADHD | Rate ratio (95% confidence intervals) | ||
---|---|---|---|
Model 1†| Model 2‡ | Model 3§ | |
Normal birth weight | Â | Â | Â |
 Low risk (ref.) | 1.00 | 1.00 | 1.00 |
 High risk | 0.98 (0.82–1.16) | 0.97 (0.83–1.14) | 0.98 (0.83–1.15) |
Birth weight 2000–2499 g |  |  |  |
 Low risk | 0.88 (0.56–1.37) | 1.04 (0.68–1.61) | 1.04 (0.68–1.61) |
 High risk | 0.85 (0.55–1.31) | 0.88 (0.56–1.38) | 0.87 (0.56–1.37) |
Birth weight <2000 g | Â | Â | Â |
 Low risk | 1.32 (0.83–2.09) | 1.32 (0.80–2.19) | 1.30 (0.79–2.16) |
 High risk | 1.82 (1.10–3.01)* | 1.68 (1.17–2.39)** | 1.64 (1.14–2.35)** |