Table 2.
Characteristics of non-ADHD subjects and ADHD patients
| Discrete | Characteristics | ||||
|---|---|---|---|---|---|
| Matched non-ADHD subjects | ADHD patients | Pvaluea | |||
| N | Col% | N | Col% | ||
| All subjects | 158,790 | 100.0 | 31,769 | 100.0 | – |
| Sex | |||||
| Females | 67,802 | 42.7 | 13,564 | 42.7 | |
| Males | 90,988 | 57.3 | 18,205 | 57.3 | – |
| ADHD treatment status | |||||
| +stimulants | – | – | 4960 | 15.6 | |
| None or unknown | – | – | 26,809 | 84.4 | – |
| Vital status | |||||
| Died during follow-up | 1248 | 0.8 | 716 | 2.3 | |
| Alive at last follow-up | 157,542 | 99.2 | 31,053 | 97.7 | <0.001 |
| Psychiatric conditions | |||||
| Diagnosis history | 3336 | 2.1 | 4005 | 12.6 | |
| No diagnosis history | 155,454 | 97.9 | 27,764 | 87.4 | <0.001 |
| Tobacco use history | |||||
| Diagnosis history | 8753 | 5.5 | 2737 | 8.6 | |
| No diagnosis history | 150,037 | 94.5 | 29,032 | 91.4 | <0.001 |
| Race and ethnicity | |||||
| White and non-Hispanic | 141,071 | 88.8 | 28,550 | 89.9 | |
| Non-white or Hispanic | 17,719 | 11.2 | 3219 | 10.1 | <0.001 |
| Continuous | Median (r) | Mean (±s.d.) | Median (r) | Mean (±s.d.) | |
|---|---|---|---|---|---|
| Years of follow-up | 21 (1–21) | 20.9 (±0.5) | 21 (1–21) | 20.8 (±1.2) | – |
| ADHD index age (years) | – | – | 26 (3–61) | 28.2 (±12.4) | – |
aχ2 test, discrete data; paired t test, continuous data; ns, not significant at the 0.05 level