Demographics and baseline characteristics of individuals who were successfully contacted compared with those who were not contacted or did not respond
| Responded (n = 4003) | Not contacted or no response (n = 4404) | p Value | |
|---|---|---|---|
| IBS, irritable bowel syndrome. | |||
| Sex | |||
| Male | 1756 (44%) | 2180 (49.5%) | <0.001 |
| Female | 2247 (56%) | 2224 (50.5%) | |
| Lifestyle | |||
| Smoker | 879 (22%) | 1324 (30%) | <0.001 |
| Alcohol user | 3642 (91%) | 3876 (88%) | <0.001 |
| Social class | |||
| I and II | 1531 (38%) | 1502 (34%) | <0.001 |
| III | 1697 (42%) | 1916 (43.5%) | |
| IV and V | 409 (10%) | 490 (11%) | |
| Baseline quality of life | |||
| High | 1237 (31%) | 1247 (28%) | 0.012 |
| Medium | 1343 (33.5%) | 1417 (32%) | |
| Low | 1269 (32%) | 1558 (35%) | |
| Dyspepsia at baseline | 1375 (34%) | 1792 (41%) | <0.001 |
| IBS at baseline | 221 (5.5%) | 246 (6%) | 0.90 |
| Mean (SD) age (years) | 55.4 (2.8) | 55.2 (2.9) | 0.30 |