Table 1.
Sociodemographic and other selected characteristics of the study population by case–control status
| Characteristics | Cases | Controls | OR* | 95% Cl | ||
| N | % | N | % | |||
| Total | 2926 | 3555 | ||||
| Gender | ||||||
| Male | 2276 | 77.8 | 2780 | 78.2 | ||
| Female | 650 | 22.2 | 775 | 21.8 | p**=0.68 | |
| Department | ||||||
| Calvados | 354 | 12.1 | 462 | 13.0 | – | – |
| Doubs et territoire de Belfort | 149 | 5.1 | 143 | 4.0 | – | – |
| Hérault | 334 | 11.4 | 450 | 12.7 | – | – |
| Isère | 476 | 16.3 | 501 | 14.1 | – | – |
| Loire Atlantique | 350 | 12.0 | 404 | 11.4 | – | – |
| Manche | 320 | 10.9 | 312 | 8.8 | – | – |
| Bas-Rhin | 398 | 13.6 | 469 | 13.2 | – | – |
| Haut-Rhin | 73 | 2.5 | 118 | 3.3 | – | – |
| Somme | 321 | 11.0 | 499 | 14.0 | – | – |
| Vendée | 151 | 5.2 | 197 | 5.5 | – | – |
| Age at interview (years) | ||||||
| <50 | 466 | 15.9 | 827 | 23.3 | 1.00 | Reference |
| 50–60 | 999 | 34.1 | 1012 | 28.5 | 1.75 | (1.51–2.02) |
| 60–70 | 989 | 33.8 | 1186 | 33.4 | 1.47 | (1.27–1.70) |
| ≥70 | 472 | 16.1 | 530 | 14.9 | 1.59 | (1.34–1.88) |
| Mean (SD) | 59.69 (9.34) | 58.52 (10.22) | p**<0.001 | |||
| Highest educational level† | ||||||
| Elementary school or less | 879 | 32.7 | 763 | 21.92 | 1.00 | Reference |
| Middle school | 1077 | 40.1 | 1351 | 38.81 | 0.64 | (0.56–0.73) |
| High school | 257 | 9.6 | 400 | 11.49 | 0.51 | (0.41–0.61) |
| University | 383 | 14.3 | 901 | 25.88 | 0.33 | (0.28–0.40) |
| Unknown | 88 | 3.3 | 23 | 2 | ||
| Cigarette smoking history | ||||||
| Never smoked‡ | 247 | 8.4 | 1326 | 37.3 | 1.00 | Reference |
| Former smokers | 995 | 34.0 | 1485 | 41.77 | 3.45 | (2.93–4.05) |
| Current smokers | 1667 | 57.0 | 742 | 20.87 | 16.35 | (12.92–18.23) |
| Missing | 17 | 0.6 | 2 | 0.06 | ||
| Cumulative cigarette consumption (CSI) | ||||||
| 0‡ | 247 | 8.4 | 1326 | 37.3 | 1.00 | Reference |
| 0–0.5 | 133 | 4.5 | 704 | 19.8 | 1.01 | (0.81–1.27) |
| 0.5–1 | 271 | 9.3 | 565 | 15.9 | 2.67 | (2.20–3.27) |
| 1–1.5 | 505 | 17.3 | 457 | 12.9 | 6.46 | (5.34–7.82) |
| 1.5–2 | 979 | 33.5 | 377 | 10.6 | 14.53 | (12.06–17.52) |
| >2 | 762 | 26.0 | 115 | 3.2 | 36.15 | (28.35–46.11) |
| Missing | 29 | 0.99 | 11 | 0.3 | ||
| Number of jobs held | ||||||
| 0 | 42 | 1.4 | 15 | 0.4 | 2.44 | (1.31–4.54) |
| 1 | 292 | 10.0 | 269 | 7.6 | 1.00 | Reference |
| 2 | 482 | 16.5 | 541 | 15.2 | 0.81 | (0.66–1.01) |
| 3 | 552 | 18.9 | 691 | 19.4 | 0.7 | (0.57–0.86) |
| 4 | 512 | 17.5 | 614 | 17.3 | 0.71 | (0.58–0.88) |
| ≥5 | 1046 | 35.7 | 1425 | 40.1 | 0.61 | (0.51–0.75) |
| Number of jobs held, mean (SD) | 4.14 (2.65) | 4.38 (2.54) | p**=0.0002 | |||
| Total duration of employment, mean (SD)† | 34.40 (10.82) | 34.02 (10.24) | P**=0.02 | |||
| Histological types | ||||||
| Squamous cell carcinoma | 906 | 31.0 | – | – | ||
| Small cell carcinoma | 429 | 14.7 | – | – | ||
| Adenocarcinoma | 1145 | 39.1 | – | – | ||
| Large cell carcinoma | 246 | 8.4 | – | – | ||
| Other types | 200 | 6.8 | – | – | ||
*OR adjusted for age at interview and department.
**p Values are derived from the Pearson’s χ2 test for categorical variables or Student's test for continuous variables.
†Only available for the complete questionnaire.
‡Non-smokers were subjects who had smoked fewer than 100 cigarettes in their lifetime.
§Former smokers were subjects who had stopped smoking at least 2 years before diagnosis (cases)/interview (controls).
CSI, Comprehensive Smoking Index.