Table 1.
Baseline Demographic and Lifestyle Characteristics of Current Smokers Who Developed Lung Cancer (Cases) and Those Who Remained Cancer-Free (Controls) in the Shanghai Cohort Study and the Singapore Chinese Health Study
| Shanghai Cohort |
Singapore Cohort |
|||||
|---|---|---|---|---|---|---|
| Cases | Controls | P* | Cases | Controls | P* | |
| Total number of subjects | 155 | 152 | 91 | 93 | ||
| Age at interview (year), mean (SD)† | 57.9 (4.8) | 57.6 (4.7) | 0.61 | 61.1 (6.5) | 61.3 (6.4) | 0.83 |
| Sex, n (%) | ||||||
| Males | 155 (100) | 152 (100) | - | 80 (87.9) | 81 (87.1) | 0.87 |
| Females | 0 (0) | 0 (0) | 11 (12.1) | 12 (12.9) | ||
| Body mass index (kg/m2), mean (SD) | 21.5 (2.8) | 21.8 (3.0) | 0.34 | 21.6 (2.8) | 22.0 (2.6) | 0.23 |
| Level of education, n (%) | ||||||
| No formal education | 18 (11.6) | 8 (5.3) | 0.12 | 28 (30.8) | 24 (25.8) | 0.61 |
| Primary school | 61 (39.4) | 60 (39.5) | 53 (58.2) | 55 (59.1) | ||
| Secondary school | 76 (49.0) | 84 (55.2) | 10 (11.0) | 14 (15.1) | ||
| No. of cigarettes per day, mean (SD) | 20.7 (7.7) | 15.3 (7.2) | <0.0001 | 19.5 (12.2) | 18.2 (14.4) | 0.50 |
| No. of years of smoking, mean (SD) | 36.7 (8.2) | 33.6 (9.1) | 0.002 | 48.2 (10.0) | 46.6 (10.7) | 0.29 |
| No. of pack-years of smoking, mean (SD) | 38.4 (16.7) | 26.0 (14.4) | <0.0001 | 47.1 (32.0) | 43.2 (33.8) | 0.42 |
| Urinary cotinine (ng/mg creatinine), mean (SD) | 3033 ( 2244) | 1972 (1573) | <0.0001 | 2873 (1758) | 2517 (1825) | 0.18 |
| Alcohol drinking, n (%) | ||||||
| Non-Drinkers | 69 (44.5) | 65 (42.8) | 0.76 | 50 (55.0) | 64 (68.8) | 0.05 |
| Regular Drinkers | 86 (55.5) | 87 (57.2) | 41 (45.0) | 29 (31.2) | ||
| No. of alcoholic drinks per day, mean (SD)‡ | 3.7 (3.2) | 2.4 (1.8) | 0.002 | 1.4 (2.2) | 1.0 (1.5) | 0.32 |
*
P-values (2-sided) were derived from t-test (for means) or χ2 (for frequencies) statistics.
†
SD, standard deviation.
‡
Among alcohol drinkers only.