Table 1.
Main characteristic of 101,721 subjects in the PLCO cancer screening trial.
| Variables | Non-cases (n = 100,945) | Cases (n = 776) | p-value |
|---|---|---|---|
| Age (years), mean ± SD | 62.4 ± 5.3 | 64.1 ± 5.2 | <0.001 |
| Sex (n, %) | |||
| Male | 48,847 (48.4) | 627 (80.8) | <0.001 |
| Female | 52,098 (51.6) | 149 (19.2) | |
| Smoking status (n, %) | |||
| Never | 48,363 (47.9) | 189 (24.4) | <0.001 |
| Current | 9264 (9.2) | 131 (16.9) | |
| Former | 43,305 (42.9) | 456 (58.8) | |
| Missing | 13 (0.0) | 0 (0.0) | |
| Education (n, %) | |||
| ≤ High school | 42,574 (42.2) | 354 (45.6) | 0.066 |
| ≥Some college | 58,177 (57.6) | 419 (54.0) | |
| Missing | 194 (0.2) | 3 (0.4) | |
| BMI (n, %) | |||
| <25.0 kg/m2 | 33,522 (33.2) | 217 (28.0) | 0.008 |
| ≥25.0 kg/m2 | 66,099 (65.5) | 549 (70.7) | |
| Missing | 1324 (1.3) | 10 (1.3) | |
| Race (n, %) | |||
| White, Non-Hispanic | 91,765 (90.9) | 738 (95.1) | <0.001 |
| Other | 9143 (9.1) | 38 (4.9) | |
| Missing | 37 (0.0) | 0 (0.0) | |
| Alcohol drinking status (n, %) | |||
| Never | 10,061 (10.0) | 52 (6.7) | 0.003 |
| Former | 14,650 (14.5) | 105 (13.5) | |
| Current | 73,368 (72.7) | 604 (77.8) | |
| Missing | 2866 (2.8) | 15 (1.9) | |
| Total energy (kcal/day), median (IQR) | 1608 (1222–2102) | 1742 (1306–2255) | <0.001 |
| Randomization arm (n, %) | |||
| Intervention | 51,440 (51.0) | 364 (46.9) | 0.025 |
| Control | 49,505 (49.0) | 412 (53.1) | |
| Marital status (n, %) | |||
| Married | 78,972 (78.2) | 639 (82.3) | 0.006 |
| Not married | 21,790 (21.6) | 134 (17.3) | |
| Missing | 183 (0.2) | 3 (0.4) | |
| Family history of any cancer (n, %) | |||
| Yes | 56,388 (56.0) | 450 (58.1) | 0.236 |
| No | 44,557 (44.0) | 326 (41.9) |
PLCO, prostate, lung, colorectal and ovarian; SD, standard deviation; BMI, body mass index; IQR, interquartile range.