Cohort characteristics by number of driving related offences*
| None (n=12 921) | One (n=4644) | Two (n=1825) | Three or more (n=1391) | Total (n=20 871) | |||
| Number (%) | Number (%) | Number (%) | Number (%) | Number | |||
| Demographics | Gender | Female | 7976 (61.7) | 2295 (49.4) | 707 (38.7) | 371 (26.7) | 11 349 |
| Male | 4945 (38.3) | 2349 (50.6) | 1118 (61.3) | 1020 (73.3) | 9432 | ||
| Age (years) | 17 | 5997 (46.4) | 2416 (52.0) | 953 (52.2) | 752 (54.1) | 10 118 | |
| 18–19 | 4880 (37.8) | 1684 (36.3) | 671 (36.8) | 493 (35.4) | 7728 | ||
| 20–25 | 2044 (15.8) | 544 (11.7) | 201 (11.0) | 146 (10.5) | 2935 | ||
| Country of birth | Australia/New Zealand | 10 960 (86.5) | 4049 (88.5) | 1634 (90.8) | 1218 (89.0) | 17 861 | |
| Other | 1706 (13.5) | 527 (11.5) | 166 (9.2) | 151 (11.0) | 2550 | ||
| Area-level SES | Least disadvantaged | 3448 (26.7) | 1053 (22.7) | 375 (20.5) | 255 (18.3) | 5131 | |
| Second quartile | 3198 (24.8) | 1154 (24.8) | 455 (24.9) | 326 (23.4) | 5133 | ||
| Third quartile | 3247 (25.1) | 1266 (27.3) | 505 (27.7) | 429 (30.8) | 5447 | ||
| Most disadvantaged | 3028 (23.4) | 1171 (25.2) | 490 (26.8) | 381 (27.4) | 5070 | ||
| Remoteness | Metro | 9668 (74.8) | 3414 (73.5) | 1349 (73.9) | 1021 (73.4) | 15 452 | |
| Inner regional | 2672 (20.7) | 1012 (21.8) | 385 (21.1) | 319 (22.9) | 4388 | ||
| Outer regional/remote | 581 (4.5) | 218 (4.7) | 91 (5.0) | 51 (3.7) | 941 | ||
| Driving and experience and training | Attempts on driver test | 1 | 8486 (65.9) | 3011 (65.0) | 1160 (63.6) | 815 (58.8) | 13 472 |
| 2 | 3028 (23.5) | 1123 (24.3) | 441 (24.2) | 364 (26.3) | 4956 | ||
| 3 or more | 1360 (10.6) | 496 (10.7) | 222 (12.2) | 207 (14.9) | 2285 | ||
| Time on learners-licence | <1 year | 4608 (35.8) | 1880 (40.6) | 786 (43.2) | 652 (47.1) | 7926 | |
| 1–1.5 years | 4615 (35.9) | 1659 (35.9) | 657 (36.1) | 473 (34.2) | 7404 | ||
| >1.5 years | 3646 (28.3) | 1086 (23.5) | 378 (20.8) | 260 (18.8) | 5370 | ||
| Crash before study | No | 12 875 (99.6) | 4352 (93.7) | 1674 (91.7) | 1266 (91.0) | 20 167 | |
| Yes | 46 (0.4) | 292 (6.3) | 151 (8.3) | 125 (9.0) | 614 | ||
| Self-rated driving ability compared with other drivers | Much better | 2041 (16.3) | 913 (20.4) | 418 (23.8) | 356 (27.1) | 3728 | |
| Better | 5459 (43.6) | 1975 (44.1) | 755 (43.0) | 569 (43.3) | 8758 | ||
| Same | 4788 (38.2) | 1529 (34.2) | 554 (31.6) | 371 (28.2) | 7242 | ||
| Worse or much worse | 239 (1.9) | 57 (1.3) | 28 (1.6) | 18 (1.4) | 342 | ||
| Lessons with professional driving instructor (hours) | 0 | 2096 (16.2) | 817 (17.6) | 401 (22.0) | 340 (24.4) | 3654 | |
| 1–4 | 3516 (27.2) | 1396 (30.1) | 563 (30.8) | 434 (31.2) | 5909 | ||
| 5–8 | 2679 (20.7) | 1011 (21.8) | 359 (19.7) | 242 (17.4) | 4291 | ||
| 9+ | 4630 (35.8) | 1420 (30.6) | 502 (27.5) | 375 (27.0) | 6927 | ||
| Drug and alcohol and mental health | Marijuana smoking in last 12 months | Never | 11 123 (88.8) | 3785 (84.8) | 1404 (80.3) | 951 (72.3) | 17 263 |
| Once a month or less | 1104 (8.8) | 511 (11.4) | 248 (14.2) | 228 (17.3) | 2091 | ||
| 2–4 times a month | 175 (1.4) | 104 (2.3) | 50 (2.9) | 71 (5.4) | 400 | ||
| 2–3 or 4+ per week | 119 (1.0) | 66 (1.5) | 46 (2.6) | 66 (5.0) | 297 | ||
| Use of other drugs in last 12 months | Never | 11 830 (94.6) | 4113 (92.3) | 1579 (90.5) | 1127 (86.1) | 18 649 | |
| Once a month or less | 528 (4.2) | 262 (5.9) | 120 (6.9) | 121 (9.2) | 1031 | ||
| 2–4 times a month | 101 (0.8) | 56 (1.3) | 32 (1.8) | 47 (3.6) | 236 | ||
| 2–3 or 4+ per week | 40 (0.3) | 27 (0.6) | 14 (0.8) | 14 (1.1) | 95 | ||
| Alcohol audit summary score | 0–6 | 11 243 (89.6) | 3791 (84.7) | 1392 (79.3) | 1012 (76.7) | 17 438 | |
| >6 | 1300 (10.4) | 686 (15.3) | 363 (20.7) | 307 (23.3) | 2656 | ||
| Self-harm | No | 11 386 (93.3) | 3963 (91.0) | 1513 (89.6) | 1107 (87.3) | 17 969 | |
| Yes | 812 (6.7) | 391 (9.0) | 176 (10.4) | 161 (12.7) | 1540 | ||
| Risky driving | Risk taking score | Low | 5123 (41.5) | 1189 (27.0) | 344 (20.0) | 194 (15.1) | 6850 |
| Medium | 4088 (33.1) | 1498 (34.0) | 533 (30.9) | 332 (25.8) | 6451 | ||
| High | 3126 (25.3) | 1719 (39.0) | 846 (49.1) | 760 (59.1) | 6451 | ||
| Risk perception score | Low | 4275 (34.8) | 1251 (28.6) | 424 (24.7) | 259 (20.4) | 6209 | |
| Medium | 3954 (32.2) | 1376 (31.5) | 484 (28.2) | 333 (26.2) | 6147 | ||
| High | 4058 (33.0) | 1743 (39.9) | 806 (47.0) | 680 (53.5) | 7287 | ||
| Sensation seeking score | Low | 4521 (36.8) | 1163 (26.6) | 337 (19.7) | 236 (18.5) | 6257 | |
| Medium | 4048 (33.0) | 1465 (33.5) | 528 (30.9) | 345 (27.1) | 6386 | ||
| High | 3710 (30.2) | 1749 (40.0) | 844 (49.4) | 692 (54.4) | 6995 | ||
| Driving exposure | Average weekly driving (hours) | Mean (SD) | 7.5 (12.7) | 9.6 (13.2) | 10.8 (11.6) | 14.6 (24.7) | 8.7 (13.9) |
*Offences from joining DRIVE study in 2003/2004 until end of 2006, missing values not shown.
SES, socioeconomic status.