Table 1.
Characteristics of cases and controls
| Characteristic | No. cases (n = 237) | No. controls (n = 711) | P‐value |
|---|---|---|---|
| Age (years) | |||
| <50 | 53 (22.4%) | 138 (19.4%) | |
| 50–59 | 67 (28.3%) | 217 (30.5%) | |
| 60–69 | 69 (29.1%) | 213 (30.0%) | |
| 70–79 | 48 (20.3%) | 143 (20.1%) | |
| Mean age (SD) | 57.9 (12.4) | 58.4 (12.0) | |
| Sex | |||
| Male | 188 (79.3%) | 564 (79.3%) | |
| Female | 49 (20.7%) | 147 (20.7%) | |
| Drinking | |||
| Never | 56 (23.6%) | 235 (33.1%) | |
| Former † | 14 (5.9%) | 37 (5.2%) | |
| Current | |||
| Moderate ‡ | 96 (40.5%) | 345 (48.5%) | |
| Heavy § | 62 (26.2%) | 83 (11.7%) | <0.01 |
| Unknown | 9 (3.8%) | 11 (1.5%) | |
| Smoking | |||
| Never | 56 (23.6%) | 256 (36.0%) | |
| Former † | 64 (27.0%) | 210 (29.5%) | |
| Current (pack years) | |||
| 0–39 | 52 (21.9%) | 134 (18.8%) | |
| ≥40 | 62 (26.2%) | 108 (15.2%) | <0.01 |
| Unknown | 3 (1.3%) | 3 (0.4%) | |
| Mean total energy (kcal/day) (SD) | 1652.0 (381.6) | 1689.1 (333.0) | 0.20 |
| Mean total non‐alcohol energy (kcal/day) (SD) | 1545.1 (358.4) | 1622.5 (327.1) | <0.01 |
| Carotene (mean ± SD, µg/day) | |||
| Tertile 1 (1829.8 ± 209.8) | 104 (43.9%) | 236 (33.2%) | |
| Tertile 2 (2667.3 ± 314.0) | 73 (30.8%) | 236 (33.2%) | |
| Tertile 3 (4394.3 ± 1317.4) | 55 (23.2%) | 236 (33.2%) | <0.01 |
| Unknown | 5 (2.1%) | 3 (0.4%) | |
| Vitamin C (mean ± SD, mg/day) | |||
| Tertile 1 (53.9 ± 9.7) | 113 (47.7%) | 237 (33.3%) | |
| Tertile 2 (82.5 ± 8.2) | 72 (30.4%) | 237 (33.3%) | |
| Tertile 3 (129.0 ± 32.9) | 47 (19.8%) | 236 (33.2%) | <0.01 |
| Unknown | 5 (2.1%) | 1 (0.1%) | |
| Vitamin E (mean ± SD, total α‐mg/day) | |||
| Tertile 1 (3.9 ± 0.6) | 96 (40.5%) | 237 (33.3%) | |
| Tertile 2 (5.5 ± 0.5) | 88 (37.1%) | 237 (33.3%) | |
| Tertile 3 (8.1 ± 1.8) | 50 (21.1%) | 236 (33.2%) | <0.01 |
| Unknown | 3 (1.3%) | 1 (0.1%) | |
| Folate (mean ± SD, µg/day) | |||
| Tertile 1 (218.5 ± 31.5) | 111 (46.8%) | 237 (33.3%) | |
| Tertile 2 (305.3 ± 23.4) | 67 (28.3%) | 237 (33.3%) | |
| Tertile 3 (435.3 ± 91.7) | 54 (22.8%) | 236 (33.2%) | <0.01 |
| Unknown | 5 (2.1%) | 1 (0.1%) | |
| Multivitamin use (at least once per week for 1 year or longer) | |||
| Yes | 32 (13.5%) | 162 (22.8%) | |
| No | 191 (80.6%) | 511 (71.9%) | 0.01 |
| Unknown | 14 (5.9%) | 38 (5.3%) | |
| Dental brushing (at least once per day) | |||
| Yes | 227 (95.8%) | 703 (98.9%) | |
| No | 10 (4.2%) | 8 (1.1%) | <0.01 |
| Referral pattern to our hospital | |||
| Self recommendation | 26 (11.0%) | 202 (28.4%) | |
| Recommendation by family or friends | 19 (8.0%) | 143 (20.1%) | |
| Referral by physicians | 177 (74.7%) | 211 (29.7%) | |
| Secondary screening | 11 (4.6%) | 148 (20.8%) | |
| Others | 0 (0%) | 4 (0.6%) | <0.01 |
| Unknown | 4 (1.7%) | 3 (0.4%) | |
†
Former smokers and drinkers were defined as subjects who had quit smoking and drinking at least 1 year previously.
‡
Moderate drinker means <46 g ethanol/drink and/or <5 days/week.
§
Heavy drinker means ≥46 g ethanol/drink and ≥5 days/week.