Returned smoking questionnaires by year, and derived smoking status for cases and non-cases
| Smoking questionnaires completed | ||||
|---|---|---|---|---|
| First survey year | n (%) | Last survey year | n (%) | |
| *202 persons with incomplete smoking information were excluded. | ||||
| 1979 | 2447 (83.4) | 1979 | 829 (28.2) | |
| 1982 | 202 (6.8) | 1982 | 79 (2.7) | |
| 1990–99 | 283 (9.6) | 1990–1999 | 1401 (47.7) | |
| 2000–01 | 3 (0.10) | 2000/01 | 626 (21.3) | |
| Total | 2935 | 2935 | ||
| Cases | Non-cases | Total | ||
| Smoking status* | n (%) | n (%) | n (%) | p value |
| Never | 3 (2.2) | 497 (19.2) | 500 (18.3) | <0.001 |
| Ex-smoker <6 years | 11 (7.9) | 46 (1.8) | 57 (2.1) | |
| Ex-smoker 6–9 years | 5 (3.6) | 55 (2.1) | 60 (2.2) | |
| Ex-smoker 10–19 years | 20 (14.5) | 308 (11.9) | 328 (12.0) | |
| Ex-smoker 20+ years | 8 (5.8) | 656 (25.3) | 664 (24.3) | |
| Current <20 per day | 28 (20.3) | 440 (16.9) | 468 (17.1) | |
| Current ⩾20 per day | 63 (45.7) | 593 (22.9) | 656 (24.0) | |
| Total | 138 | 2595 | 2733 | |