Characteristics of responders and non-responders
| Respondents at follow-up (n=3149) | Non-respondents at follow-up (n=12 390) | |
| Male, % (n) | 46.2 (1454) | 52.7 (6524)* |
| Age, mean (SD) | 46.1 (15.42) | 38.9 (15.93)* |
| Social grade, % (n) | ||
| AB | 17.8 (559) | 14.7 (1823) |
| C1 | 24.0 (757) | 25.5 (3158) |
| C2 | 23.8 (748) | 24.8 (3070) |
| D | 21.0 (660) | 22.2 (2747) |
| E | 13.4 (423) | 12.8 (1592) |
| Cigarettes per day, mean (SD) | 14.1 (8.61) | 13.0 (8.37)* |
| Smoke within 30 min of waking, % (n)* | 55.8 (1756) | 53.0 (6567)* |
Table entries are weighted to match the 2001 census.
↵* Significant difference between responders and non-responders, p<0.001, detected using χ2 test for percentages and t-test for means.