Selected characteristics of case and control groups, Montreal, 1979–85
| Characteristic | Oesophageal cancer cases (n=99) | Population controls (n=533) | Cancer controls (n=2299) | Pooled controls2-150 (n=1066) |
| Mean age (y) | 59.6 | 59.6 | 58.6 | 59.2 |
| Educational level (%): | ||||
| 0–6 y | 25.3 | 20.3 | 22.5 | 22.2 |
| 7–12 y | 60.6 | 56.1 | 55.2 | 55.6 |
| ⩾13 y | 14.1 | 23.6 | 22.3 | 22.1 |
| Birthplace (%): | ||||
| Québec province | 76.2 | 74.0 | 70.2 | 73.1 |
| Rest of Canada, USA | 7.1 | 6.6 | 7.8 | 6.1 |
| Southern Europe | 7.1 | 9.4 | 9.0 | 9.9 |
| Northern Europe | 6.1 | 6.0 | 9.4 | 7.3 |
| Asia, Africa | 1.0 | 3.0 | 2.3 | 2.4 |
| Other | 2.0 | 1.1 | 1.3 | 1.0 |
| Respondent (%): | ||||
| Self | 67.7 | 87.4 | 80.5 | 84.1 |
| Proxy | 32.3 | 12.6 | 19.5 | 15.9 |
| Beer consumption (%): | ||||
| None or social | 37.4 | 70.9 | 64.7 | 67.8 |
| Medium | 31.3 | 23.6 | 25.5 | 24.8 |
| Heavy | 31.3 | 5.4 | 9.8 | 7.4 |
| Spirits consumption (%): | ||||
| None or social | 66.7 | 85.2 | 79.6 | 81.6 |
| Medium | 17.2 | 11.6 | 13.6 | 13.6 |
| Heavy | 16.2 | 3.2 | 6.9 | 4.8 |
| β-Carotene index (%): | ||||
| Low | 55.6 | 31.3 | 47.8 | 40.1 |
| Medium | 27.3 | 36.4 | 25.8 | 30.6 |
| High | 17.2 | 32.3 | 26.4 | 29.4 |
| Mean cigarette-years | 1213 | 802 | 845 | 807 |
| Smoking patterns (%): | ||||
| Never smokers | 7.1 | 19.7 | 17.2 | 18.9 |
| Stopped ⩾11 y | 17.2 | 19.9 | 23.1 | 19.9 |
| Stopped 3–10 y | 11.1 | 14.8 | 11.6 | 12.9 |
| Current smokers and stopped ⩽2 y | 64.6 | 45.6 | 48.2 | 48.3 |
↵2-150 This group includes the 533 population controls plus 533 selected at random from among the cancer controls.