Table 3. Association between household income trajectories and occurrence of ADHD by 10–11 years.
| HR | 95% CI | ||
|---|---|---|---|
| Income trajectory | |||
| Consistently low | 1.476 | 1.048 | 2.079 |
| Consistently mid-low | 1.363 | 1.077 | 1.726 |
| Mid-low to mid-high | 1.062 | 0.773 | 1.459 |
| Consistently mid-high | 1.000 | ||
| Decreasing | 1.689 | 1.197 | 2.382 |
| Mid-high to high | 0.909 | 0.546 | 1.514 |
| Consistently high | 1.134 | 0.892 | 1.442 |
| Sex | |||
| Men | 2.954 | 2.414 | 3.614 |
| Women | 1.000 | ||
| Location | |||
| Rural | 1.000 | ||
| Urban | 1.497 | 1.226 | 1.828 |
| Low birth weight (<2500 g) | |||
| No | 1.000 | ||
| Yes | 1.302 | 0.580 | 2.922 |
| Conduct disorders (aggressive disorder, oppositional defiant disorder) | |||
| No | 1.000 | ||
| Yes | 6.442 | 3.133 | 13.249 |
| Emotional disorders (depression, anxiety) | |||
| No | 1.000 | ||
| Yes | 5.586 | 4.050 | 7.704 |
| Social disorders | |||
| No | 1.000 | ||
| Yes | 8.987 | 4.845 | 16.670 |
| Tic disorders | |||
| No | 1.000 | ||
| Yes | 3.525 | 2.424 | 5.126 |
| Autism spectrum disorders | |||
| No | 1.000 | ||
| Yes | 3.048 | 1.594 | 5.832 |
| Developmental disorders | |||
| No | 1.000 | ||
| Yes | 4.259 | 3.050 | 5.946 |
| Intellectual disability | |||
| No | 1.000 | ||
| Yes | 2.352 | 1.375 | 4.022 |
| Year of birth | |||
| 2002 | 1.054 | 0.887 | 1.253 |
| 2003 | 1.000 | ||
ADHD, attention deficit hyperactivity disorder; CI, confidence interval; HR, hazard ratio.