Table 1.
Sample Characteristics of the 1,701,206 Adults in the Study Population, All Born From 1967 to 1997 and Followed Until 2015
| Variable | ADHD | ASD | ADHD+ASD | Remaining Population |
|---|---|---|---|---|
| Population | 38,636 (2.3) | 7528 (0.4) | 1467 (0.1) | 1,653,575 (97.2) |
| Women | 17,393(45.0), p <.001a | 2099 (27.9), p =.491b | 422 (28.8), p <.001c | 809,962 (49.0), p <.001d |
| Male/Female Ratio | 1.22 | 2.58 | 2.48 | 1.04 |
| Age in 2015, Years | 31.3 ± 8.3, p <.001a | 26.2 ± 7.9, p =.99b | 26.8 ± 7.1, p <.001c | 33.2 ± 9.3, p <.001d |
| Maternal Age at Birth | p <.001a | p <.001b | p <.001c | p <.001d |
| <20 years | 4417(11.4) | 372 (4.9) | 107(7.3) | 112,674(6.8) |
| 20–24 years | 13,587 (35.2) | 1936(25.7) | 435 (29.7) | 498,264 (30.1) |
| 25–29 years | 11,865 (30.7) | 2539 (33.7) | 525 (35.8) | 575,743 (34.8) |
| 30–34 years | 6144(15.9) | 1747(23.2) | 279 (19.0) | 327,637(19.8) |
| 35–39 years | 2215(5.7) | 774 (10.3) | 102 (7.0) | 116,139 (7.0) |
| 40+ years | 408(1.1) | 160(2.1) | 19(1.3) | 23,118(1.4) |
| Paternal Age at Birth | p <.001a | p <.001b | p <.001c | p <.001d |
| <20 years | 1054(2.7) | 75 (1.0) | 21 (1.4) | 24,546 (1.5) |
| 20–24 years | 9013 (23.3) | 1093 (14.5) | 267 (18.2) | 302,939(18.3) |
| 25–29 years | 12,941 (33.5) | 2242 (29.8) | 484 (33.0) | 563,896 (34.1) |
| 30–34 years | 8728 (22.6) | 2120(28.2) | 392 (26.7) | 432,678 (26.2) |
| 35–39 years | 4086(10.6) | 1154 (15.3) | 182 (12.4) | 207,833(12.6) |
| 40–44 years | 1621 (4.2) | 519 (6.9) | 78 (5.3) | 76,947 (4.7) |
| 45–49 years | 489(1.3) | 171 (2.3) | 25(1.7) | 24,796 (1.5) |
| 50+ years | 183(0.5) | 70 (0.9) | 3 (0.2) | 8741 (0.5) |
| Missing | 521 (1.4) | 84(1.1) | 15(1.0) | 11,199(0.7) |
| Maternal Marital Statusd | p <.001a | p <.007b | p =.016c | p <.001d |
| Single | 6483(16.8) | 909 (12.1) | 225 (15.3) | 151,975(9.2) |
| Married/cohabiting | 31,122 (80.6) | 6508 (86.5) | 1220 (83.2) | 1,482,685 (89.7) |
| Other | 924 (2.4) | 96(1.3) | 20 (1.4) | 16,154(1.0) |
| Missing | 107(0.3) | 15(0.2) | 2 (0.1) | 2761 (0.2) |
| Maternal Education Status | p <.001a | p =.169b | p <.001c | p <.001d |
| Low | 13,498(34.9) | 1904 (25.3) | 394 (26.9) | 430,874 (26.1) |
| Middle | 16,478(42.7) | 3022 (40.1) | 583 (39.7) | 768,773 (46.5) |
| High | 8415(21.8) | 2565 (34.1) | 488 (33.3) | 447,380 (27.1) |
| Missing | 245 (0.6) | 37 (0.5) | 2 (0.1) | 6548 (0.4) |
| Paternal Education Status | p <.001a | p <.001b | p <.001c | p <.001d |
| Low | 12,501 (32.4) | 1639(21.8) | 388 (26.5) | 381,154(23.1) |
| Middle | 18,626(48.2) | 3486 (46.3) | 694 (47.3) | 834,541 (50.5) |
| High | 6475 (16.8) | 2237 (29.7) | 352 (24.0) | 414,399 (25.1) |
| Missing | 1034(2.7) | 166(2.2) | 33 (2.3) | 23,481 (1.4) |
| Maternal Psychiatric Disorder | p =.073a | p <.001b | p =.001c | p <.001d |
| None | 28,140(72.8) | 5557 (73.8) | 1009 (68.8) | 1,432,294(86.6) |
| Paternal Psychiatric Disorder | p <.001a | p =.010b | p =.492c | p <.001d |
| None | 31,478 (82.7) | 6289 (84.7) | 1189 (82.0) | 1,479,367 (90.2) |
Values are n (%) or mean 6 SD.
ADHD, attention-deficit/hyperactivity disorder; ASD, autism spectrum disorder.
a
Difference between the ADHD and ASD cases (Pearson chi-square test and t test for equality of means).
b
Difference between the ASD and ADHD1ASD cases (Pearson chi-square test and t test for equality of means).
c
Difference between the ADHD and ADHD1ASD cases (Pearson chi-square test and t test for equality of means).
d
Difference between cases relative to the comparison population (Pearson chi-square test and t test for equality of means).