Table 1.
Frequency distributions of selected variables among EOC cases and controls.
| Variables | Case (n = 549) n (%) |
Control (n = 571) n (%) |
P a |
|---|---|---|---|
| Age (years) | |||
| ≤55 | 277 (50.46) | 303 (53.06) | 0.382 |
| >55 | 272 (49.54) | 268 (46.94) | |
| Age at menarche (years) | |||
| <15 | 211 (53.55) | 257 (46.73) | 0.039∗ |
| ≥15 | 183 (46.45) | 293 (53.27) | |
| Unclear | 155 (—) | 21 (—) | |
| Number of births | |||
| 0 | 16 (2.91) | 11 (1.93) | <0.001 |
| 1–3 | 409 (74.50) | 490 (85.81) | |
| ≥4 | 124 (22.59) | 70 (12.26) | |
| Menstrual history | |||
| Premenopause | 152 (27.69) | 131 (22.94) | 0.068 |
| Menopause | 397 (72.31) | 440 (77.06) | |
| Oral contraceptive use | |||
| Never | 414 (82.31) | 399 (75.86) | 0.039∗ |
| Seldom | 56 (11.13) | 78 (14.83) | |
| Often | 33 (6.56) | 49 (9.32) | |
| Unclear | 46 (—) | 45 (—) | |
| Family history of cancer | |||
| Yes | 40 (7.29) | 38 (6.65) | 0.678 |
| No | 509 (92.71) | 533 (93.35) | |
| Smoking status | |||
| Ever | 68 (12.39) | 54 (9.46) | 0.116 |
| Never | 481 (87.61) | 517 (90.54) | |
| Pack-years smoked | |||
| ≥20 | 36 (6.56) | 18 (3.15) | 0.029 |
| <20 | 32 (5.83) | 36 (6.30) | |
| 0 | 481 (87.61) | 517 (90.54) | |
| Alcohol intake | |||
| Ever | 34 (6.19) | 49 (8.58) | 0.127 |
| Never | 515 (93.81) | 522 (91.42) | |
| Staging | |||
| I + II | 43 (7.84) | ||
| III | 420 (76.50) | ||
| IV | 86 (15.66) |
a P values for a χ2 test.
∗Statistical analysis excluded subjects with unclear or unknown data.