TABLE 1.
Descriptive statistics of participant characteristics and study variables for the four cohort studies
| Variable | 25Up (N = 2,133) | S4S (N = 2,994) | NTR (N = 12,120) | UKB (N = 426,446) | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| N | Range/n | M (SD) / % | N | Range/n | M (SD) / % | N | Range/n | M (SD) / % | N | Range/n | M (SD) / % | |
| Demographics | ||||||||||||
| Age | 2,131 | 21.8–44.2 | 30.1 (4.3) | 2,452 | 18.1–32.1 | 20.7 (1.5) | 12,013 | 18.0–94.0 | 44.8 (16.9) | 426,446 | 36.0–72.0 | 54.7 (8.0) |
| % Male | 2,133 | 832 | 39.0% | 2,994 | 1,255 | 41.9% | 12,120 | 4,564 | 37.7% | 426,446 | 196,462 | 46.1% |
| % No/primary education a | 2,132 | 250 | 11.7% | 2,963 | 5 | 0.2% | 9,471 | 295 | 3.1% | 426,446 | 75,577 | 17.7% |
| % Secondary education | 572 | 26.8% | 238 | 8.0% | 1,954 | 20.6% | 114,042 | 26.7% | ||||
| % Certificate or diploma | 890 | 41.7% | 425 | 14.3% | 2,892 | 30.5% | 98,540 | 23.1% | ||||
| % Masters/postgraduate/PhD | 420 | 19.7% | 2,295 | 77.5% | 4,330 | 45.7% | 138,287 | 32.4% | ||||
| Lifetime substance use | ||||||||||||
| % Ever used tobacco | 2,128 | 1,496 | 70.3% | 2,876 | 1,949 | 67.8% | 11,870 | 5,745 | 48.4% | 425,114 | 259,676 | 61.1% |
| % Ever used cannabis | 2,118 | 1,331 | 62.8% | 2,953 | 1,966 | 66.6% | 10,012 | 2,412 | 24.1% | 138,524 | 30,627 | 22.1% |
| % Ever used other substance(s) b | 2,062 | 1,104 | 53.5% | 2,968 | 1,067 | 36.0% | 10,055 | 1,153 | 11.5% | NA | NA | NA |
| Age at initiation of substance use | ||||||||||||
| M age alcohol initiation | 1,995 | 11–33 | 16.1 (1.9) | 2,469 | 11–22 | 16.5 (1.8) | 9,762 | 11–30 | 15.8 (2.1) | NA | NA | NA |
| M age tobacco initiation | 471 | 11–34 | 17.7 (3.5) | 1,554 | 11–21 | 15.9 (2.0) | 6,862 | 11–30 | 15.4 (2.3) | 32,381 | 11–69 | 17.9 (5.7) |
| M age cannabis initiation | 1,275 | 12–36 | 18.4 (3.5) | 1,393 | 11–19 | 14.4 (2.0) | 9,729 | 11–40 | 17.9 (3.3) | NA | NA | NA |
| M age other substance initiation | 1,037 | 11–37 | 20.2 (3.9) | 617 | 11–24 | 15.1 (2.1) | 11,381 | 11–40 | 21.4 (5.2) | NA | NA | NA |
| Average substance use | ||||||||||||
| M alcohol units per month | 1,929 | 1–395 | 25.2 (37.7) | 2,594 | 0–199 | 23.1 (30.4) | 8,670 | 0–192 | 34.9 (27.3) | 304,654 | 0–200 | 8.8 (7.8) |
| M cigarettes per day | 430 | 0–30 | 5.3 (7.4) | 1,422 | 1–4 | 1.3 (0.6) | 4,819 | 0–60 | 13.8 (9.4) | 132,310 | 1–140 | 18.3 (10.1) |
| M tobacco using days | 430 | 1–30 | 14.8 (13.4) | 1,817 | 1–28 | 6.4 (8.5) | 2,016 | 4–30 | 23.7 (9.9) | NA | NA | NA |
| Regular substance (ab)use | ||||||||||||
| % Regular alcohol use | 2,062 | 450 | 21.8% | 2,662 | 220 | 8.3% | 11,081 | 2,722 | 24.6% | 138,693 | 42,564 | 30.7% |
| M problematic alcohol use (AUDIT) | NA | NA | NA | 2,603 | 0–11 | 3.5 (2.7) | 6,248 | 0–34 | 4.1 (3.6) | 138,682 | 0–39 | 5.0 (4.2) |
| % Regular tobacco use | 1,490 | 489 | 32.8% | 2,979 | 427 | 14.3% | 8,051 | 2,386 | 29.6% | 299,866 | 133,640 | 44.6% |
| M nicotine dependence (FTND) | NA | NA | NA | 1,553 | 0–9 | 1.1 (1.9) | 4,475 | 0–10 | 2.8 (2.4) | 132,541 | 0–9 | 1.8 (1.9) |
| % Regular cannabis use | 1,317 | 303 | 23.0% | 2,953 | 397 | 13.4% | 1,493 | 232 | 15.5% | 29,704 | 10,465 | 35.2% |
| % Any behavioral/substance addiction | NA | NA | NA | NA | NA | NA | NA | NA | NA | 137,122 | 8,278 | 6.0% |
| Sexual risk behavior | ||||||||||||
| M number of sexual partners | 1,719 | 0–300 | 13.3 (24.4) | 1,023 | 0–25 | 1.3 (1.8) | NA | NA | NA | 351,099 | 1–300 | 6.6 (13.0) |
| M/% sexual risk behavior | 1,925 | 0–10 | 2.1 (2.4) | 1,014 | 375 | 37.0% | NA | NA | NA | NA | NA | NA |
| M age at first sexual intercourse | NA | NA | NA | 919 | 11–28 | 16.3 (3.1) | 1,071 | 12–18 | 17.1 (1.2) | 375,311 | 11–69 | 19.1 (3.8) |
| Self‐control | ||||||||||||
| M disinhibition | NA | NA | NA | 2,757 | 1–18 | 11.0 (2.1) | 9,785 | 5–25 | 14.2 (3.7) | NA | NA | NA |
| M sensation seeking | NA | NA | NA | NA | NA | NA | 9,229 | 4–20 | 11.3 (2.5) | NA | NA | NA |
| % risk‐taking proneness | NA | NA | NA | NA | NA | NA | NA | NA | NA | 412,571 | 111,571 | 27.0% |
| M/% ADHD | 2,051 | 7–88 | 39.0 (10.4) | 657 | 106 | 16.1% | 8,046 | 0–12 | 2.3 (1.9) | NA | NA | NA |
Note: The variations in sample sizes are due to question branching and the pooling of data of several measurement waves. N = total number of participants with phenotypic and genetic data available per variable and subsample; range = minimum and maximum score/answer; n = number of participants scoring positive on this variable within the subsample; M = mean within this cohort; SD = standard deviation within this cohort; % = percentage of the total number of participants in a subsample.
Abbreviations: 25Up, 25 and Up; ADHD, attention deficit‐/hyperactivity disorder; AUDIT, Alcohol Use Disorders Identification Test; FTND, Fagerström Test for Nicotine Dependence; NTR, Netherlands Twin Register; S4S, Spit for Science; UKB, UK Biobank.
Education levels of participants or their parents in the S4S study.
Includes the use of other substances than alcohol, tobacco, and cannabis.