Table 1. Demographics.
| Cohort | DNBC* | COPSAC2000 | |||
| All N (%) | All N (%) | Female N (%) | Male N (%) | P value† | |
| Gender | 44 485 (58.6 female) | 370 (90) | 188 (50.8) | 182 (49.2) | 0.35 |
| Parents’ divorce | 13 394 (30.1) | 142 (38.4) | 74 (39.4) | 68 (37.4) | 0.77 |
| Race (Caucasian) | N/A | 355 (96.0) | 183 (97.3) | 172 (95.0) | 0.34 |
| Proband education | |||||
| Elementary school, completed | N/A | 357 (96.5) | 182 (96.8) | 175 (96.2) | 1.00 |
| College, started | 35 280 (83.6) | 288 (77.8) | 155 (82.4) | 133 (73.1) | 0.07 |
| Tradesman, started | 4331 (10.3) | 38 (10.3) | 9 (4.8) | 29 (15.9) | <0.01 |
| University, started | 361 (0.9) | 1 (0.3) | – | 1 (0.51) | – |
| Parents education, completed | |||||
| Elementary school, mother | N/A | 13 (3.51) | 8 (4.26) | 5 (2.74) | 0.41 |
| Elementary school, father | N/A | 17 (4.60) | 11 (5.85) | 6 (3.30) | 0.23 |
| High school, mother | N/A | 6 (1.62) | 6 (3.19) | – | – |
| High school, father | N/A | 7 (1.89) | 5 (2.66) | 2 (1.10) | 0.26 |
| Tradesman, mother | N/A | 94 (25.4) | 39 (20.7) | 55 (30.2) | 0.10 |
| Tradesman, father | N/A | 102 (27.6) | 47 (25.0) | 55 (30.2) | 0.43 |
| University, medium long, mother | N/A | 125 (33.8) | 62 (33.0) | 63 (34.6) | 0.93 |
| University, medium long, father | N/A | 70 (18.9) | 35 (18.6) | 35 (19.2) | 1.00 |
| University, long, mother | N/A | 69 (18.6) | 41 (21.8) | 28 (15.4) | 0.12 |
| University, long, father | N/A | 82 (22.2) | 40 (21.3) | 42 (23.1) | 0.83 |
| Fireplace | |||||
| 1–100 days | N/A | 137 (37) | 63 (33.5) | 74 (40.7) | 0.20 |
| >100 days | N/A | 38 (10.3) | 18 (9.6) | 20 (11.0) | 0.53 |
| Furred animals | |||||
| Cats, yes | N/A | 100 (27.0) | 52 (27.7) | 48 (26.4) | 0.87 |
| Dogs, yes | N/A | 181 (48.9) | 96 (51.1) | 85 (46.7) | 0.46 |
| Other children younger, yes | N/A | 218 (58.9) | 105 (55.9) | 113 (62.1) | 0.47 |
| Other children older, yes | N/A | 87 (23.5) | 46 (24.5) | 41 (22.5) | 0.89 |
| Current smoking | 9639 (21.7) | 116 (31.4) | 58 (30.9) | 58 (31.9) | 0.38 |
| Every day‡ | 3335 (34.6) | 28 (24.1) | 15 (25.9) | 13 (22.4) | 0.71 |
| Min ones every week‡ | 2193 (22.8) | 37 (31.9) | 15 (25.9) | 22 (37.9) | 0.25 |
| Min ones every month‡ | 4111 (42.7) | 51 (44.0) | 28 (48.2) | 23 (39.7) | 0.48 |
| Number of cigarettes smoked in the last 4 weeks§ | |||||
| 1–4 per day | 2879 (52.1) | 82 (80.4) | 36 (73.5) | 46 (86.8) | 0.35 |
| 5–9 per day | 1326 (24) | 11 (10.8) | 9 (18.4) | 2 (3.8) | 0.08 |
| >9 per day | 1189 (21.5) | 9 (8.8) | 4 (8.1) | 5 (9.4) | 0.74 |
| Passive smoking | |||||
| 1–100 days per year | N/A | 116 (31.4) | 58 (30.9) | 58 (31.9) | 0.92 |
| >100 days per year | N/A | 110 (29.7) | 61 (32.4) | 49 (26.9) | 0.29 |
| Drug use ever | 14 673 (33) | 87 (23.8) | 31 (16.8) | 56 (30.8) | 0.69 |
| Hash/pot | 13 907 (94.8) | 60 (70.0) | 23 (74.2) | 37 (66.1) | 0.06 |
| Cocaine | 1804 (12.3) | 22 (25.3) | 8 (25.8) | 14 (25.0) | 0.26 |
| Laughing gas (NO) | 1464 (10) | 18 (20.7) | 3 (9.7) | 15 (26.8) | 0.01 |
| Ecstasy/MDMA/fantasy | 1317 (9) | 12 (13.9) | 5 (16.1) | 7 (12.5) | 0.75 |
| Others¶ | 2979 (20.3) | 34 (39.1) | 11 (35.5) | 23 (41.1) | 0.04 |
| Alcohol; drinking frequency | |||||
| Never | 3273 (7.4) | 3 (1.0) | – | 3 (1.6) | 0.14 |
| Max once per month | 10 017 (22.5) | 89 (24.1) | 49 (26.1) | 40 (22.0) | 0.46 |
| >1 per month | 21 195 (70.1) | 253 (68.4) | 124 (66.0) | 129 (70.9) | 0.46 |
| Alcohol; units | |||||
| 1–4 | 11 853 (28.8) | 88 (23.8) | 51 (27.1) | 37 (20.3) | 0.26 |
| 5–9 | 21 952 (53.3) | 172 (46.5) | 93 (49.5) | 79 (43.4) | 0.41 |
| >10 | 7407 (18) | 82 (22.2) | 29 (15.4) | 53 (29.1) | 0.91 |
| BMI<18.5 (%) underweight | 4395 (9.9) | 32 (8.7) | 17 (9.20) | 15 (8.2) | 0.72 |
| BMI 18.5–24.99 (%) normal weight | 32 336 (72.7) | 249 (67.8) | 121 (65.4) | 128 (70.3) | 0.66 |
| BMI 25–30 (%) overweight | 5770 (13) | 57 (15.5) | 31 (16.8) | 26 (14.3) | 0.51 |
| BMI>30 (%) obese | 1984 (4.5) | 29 (7.9) | 16 (8.7) | 13 (7.1) | 0.58 |
| Screen time | |||||
| Total screen time hours, median (IQR) | N/A | 6.0 (4.5–7.0) | 5.90 (4.5–6.5) | 6.7 (5.0–7.9 | <0.01 |
| Asthma, current | N/A | 93 (25.1) | 46 (24.4) | 47 (25.8) | 0.85 |
| Self-injury | N/A | 73 (21) | 56 (31.1) | 17 (9.9) | 0.92 |
| Self-esteem all (mean/SD) | N/A | 3.58/0.80 | |||
| 1 | 5 (1.35) | 3 (3.23) | 2 (1.10) | 1.00 | |
| 2 | 18 (4.86) | 12 (12.9) | 6 (3.30) | 0.26 | |
| 3 | 142 (38.4) | 81 (87.1) | 61 (33.5) | 0.08 | |
| 4 | 162 (43.8) | 77 (82.80) | 85 (46.7) | 0.29 | |
| 5 | 40 (10.8) | 14 (15.1) | 26 (14.3) | 0.05 | |
| Neuropsychiatric disorder ever | N/A | 62 (16.8) | 30 (16.0) | 32 (17.6) | 0.80 |
Bold values represent p-values at or below the significance level of 0.05.
*
Absolute and relative frequencies for a sample of complete response observations from the 18-year DNBC follow-up.
†
t-test comparing significance between the gender.
‡
Only for current smokers.
§
Only for current smokers. Data are available from 102 probands.
¶
Amphetamine, sedatives, LSD, opiates, euphoric mushrooms, lighter gas.
BMIbody mass indexCOPSAC2000Copenhagen Prospective Study on Asthma in ChildhoodDNBCDanish National Birth CohortLSDLysergic Acid DiethylamideMDMA3,4-Methylenedioxy-methamphetamineN/Anot available