Descriptive characteristics of the overall cohort and period-specific samples. The Tromsø Study 1974-2016
| Cohort | Overall cohort | Period-specific samples* | ||||
| Tromsø 1–7 (1974–2016) | Tromsø 1–3 (1974–1986) | Tromsø 2–4 (1979–1995) | Tromsø 3–5 (1985–2001) | Tromsø 4–6 (1994–2008) | Tromsø 5–7 (2001–2016) | |
| Baseline | Examination 2 | Tromsø 2 (1979–1980) | Tromsø 3 (1986–1987) | Tromsø 4 (1994–1995) | Tromsø 5 (2001) | Tromsø 6 (2007–2008) |
| Total N (%) | 11 308 (100) | 3570 (100) | 9679 (100) | 3827 (100) | 2212 (100) | 1146 (100) |
| Sex, n (%) | ||||||
| Female | 5482 (48.8) | N/A | 4820 (49.8) | 2023 (52.8) | 1183 (53.5) | 611 (53.3) |
| Male | 5826 (51.2) | 3570 (100%) | 4859 (50.2) | 1806 (47.2) | 1029 (46.5) | 535 (46.6) |
| Age (years), n (%) | ||||||
| ≤39 | 4072 (36.0) | 1819 (51) | 3831 (39.6) | 673 (17.6) | 102 (4.6) | 32 (2.8) |
| 40–49 | 2461 (21.8) | 1186 (33.2) | 3509 (36.3) | 342 (8.9) | 341 (15.4) | 251 (21.9) |
| 50–59 | 2561 (22.6) | 565 (15.8) | 2107 (21.8) | 1977 (51.7) | 689 (31.1) | 291 (25.4) |
| 60–69 | 1981 (17.5) | N/A | 232 (2.4) | 831 (21.7) | 944 (42.7) | 465 (40.6) |
| ≥70 | 233 (2.0) | N/A | N/A | 4 (0.1) | 136 (6.) | 107 (9.3) |
| Smoking, n (%) | ||||||
| Current smoker | 4480 (39.6) | 1705 (47.8) | 4221 (43.6) | 1263 (33.0) | 579 (26.2) | 196 (17.1) |
| Previous smoker | 1790 (15.8) | 503 (14.1) | 754 (7.8) | 390 (10.2) | 843 (38.1) | 517 (45.1) |
| Never smoker | 5038 (44.6) | 1362 (38.2) | 4704 (48.6) | 2174 (56.8) | 790 (35.7) | 433 (37.8) |
| Education, n (%) | ||||||
| Primary school | 4698 (41.5) | 1842 (51.6) | 4324 (44.7) | 1456 (38.0) | 782 (35.3) | 299 (26.1) |
| High school | 3610 (31.9) | 1002 (28.1) | 2936 (30.3) | 1408 (36.8) | 665 (30.0) | 419 (36.6) |
| University<4 years | 1641 (14.5) | 423 (11.8) | 1380 (14.3) | 551 (14.4) | 364 (16.5) | 209 (18.2) |
| University≥4 years | 1359 (12.0) | 303 (8.5) | 1039 (10.7) | 412 (10.8) | 401 (18.1) | 219 (19.1) |
*Period-specific samples include all participants meeting our inclusion criteria for that period (ie, these samples do not add up to the overall cohort (Tromsø 1–7), which includes participants with their three most recent attendances).