| Characteristic | Absence of oesophagitis (n = 911) | Presence of oesophagitis (n = 122) | RR* (95% CI) |
| n (%) | n (%) | ||
| Age (years) | |||
| 32–44 | 160 (17.6) | 15 (12.3) | 1.0 |
| 45–54 | 246 (27.0) | 33 (27.0) | 1.2 (0.6 to 2.1) |
| 55–64 | 182 (20.0) | 32 (26.2) | 1.3 (0.7 to 2.4) |
| ⩾65 | 323 (35.5) | 42 (34.4) | 1.1 (0.6 to 2.0) |
| Sex | |||
| Male | 451 (49.5) | 77 (63.1) | 1.7 (1.1 to 2.7) |
| Female | 460 (50.5) | 45 (36.9) | 1.0 |
| Body mass index (kg/m2)† | |||
| <20.0 | 30 (3.3) | 3 (2.5) | 1.2 (0.4 to 3.9) |
| 20.0–24.9 | 355 (39.0) | 38 (31.1) | 1.0 |
| 25.0–29.9 | 351 (38.5) | 54 (44.3) | 1.2 (0.8 to 1.8) |
| ⩾30.0 | 166 (18.2) | 26 (21.3) | 1.0 (0.6 to 1.8) |
| Smoker | |||
| Never | 485 (53.2) | 60 (49.2) | 1.0 |
| Former | 251 (27.6) | 35 (28.7) | 1.0 (0.6 to 1.6) |
| Current | 175 (19.2) | 27 (22.1) | 1.2 (0.7 to 1.9) |
| Alcohol consumption | |||
| None/occasional | 340 (37.3) | 47 (38.5) | 1.0 |
| Weekly | 154 (16.9) | 13 (10.7) | 0.6 (0.3 to 1.2) |
| Daily | 417 (45.8) | 62 (50.8) | 0.9 (0.6 to 1.4) |
| Other factors | |||
| Coffee consumption‡ | 724 (79.5) | 93 (76.2) | 0.8 (0.5 to 1.3) |
| Medication useठ| 76 (8.3) | 11 (9.0) | 1.1 (0.6 to 2.0) |
| Patient-reported history of | |||
| peptic ulcer disease‡ | 148 (16.2) | 24 (19.7) | 1.0 (0.6 to 1.5) |
| Helicobacter pylori infection‡ | 527 (57.8) | 69 (56.6) | 1.0 (0.7 to 1.4) |
| Hiatus hernia‡ | 353 (38.7) | 91 (74.6) | 3.3 (2.2 to 5.0) |
| Reflux symptom frequency | |||
| None | 535 (58.7) | 40 (32.8) | 1.0 |
| Less than twice a week | 183 (20.1) | 30 (24.6) | 1.9 (1.2 to 3.0) |
| At least twice a week | 193 (21.2) | 52 (42.6) | 2.6 (1.7 to 3.9) |
*RRs were adjusted for all variables in the table.
†Body mass index was unknown in nine individuals with no oesophagitis and one individual with oesophagitis.
‡RRs and 95% CIs were calculated with the absence of the studied factor as the reference category in each case.
§Defined as the use of aspirin (n = 47), non-steroidal anti-inflammatory drugs (n = 32) or corticosteroids (n = 8).
CI, confidence interval; RR, relative risk.