Table 1 Characteristics of the study population
n (%) | Total, n = 3739 | Screeners, n = 1089 (29.1) | Non-screeners, n = 2260 (60.4) | Unaware, n = 390 (10.4) | P |
|---|---|---|---|---|---|
Site, n (%) | Â | Â | Â | Â | Â |
 CGH | 377 (10.1) | 79 (7.3) | 239 (10.6) | 59 (15.1) | <0.001 |
 KKH | 724 (19.4) | 173 (15.9) | 476 (21.1) | 75 (19.2) |  |
 NCC | 704 (18.8) | 260 (23.9) | 391 (17.3) | 53 (13.6) |  |
 NTFGH | 32 (0.9) | 7 (0.6) | 23 (1.0) | 2 (0.5) |  |
 NUH | 630 (16.8) | 164 (15.1) | 398 (17.6) | 68 (17.4) |  |
 SGH | 318 (8.5) | 107 (9.8) | 185 (8.2) | 26 (6.7) |  |
 TTSH | 954 (25.5) | 299 (27.5) | 548 (24.2) | 107 (27.4) |  |
Sociodemographic factors | |||||
 Age at diagnosis (years, IQR) | |||||
|  | 60.0 (55.0–66.0) | 58.0 (54.0–64.0) | 60.0 (55.0–66.0) | 66.0 (59.0–73.0) | <0.001 |
 Age at diagnosis (categorical), n (%) | |||||
  50–59 | 1800 (48.1) | 610 (56.0) | 1084 (48.0) | 106 (27.2) | <0.001 |
  ≥60 | 1939 (51.9) | 479 (44.0) | 1176 (52.0) | 284 (72.8) |  |
 Ethnicity, n (%) |  |  |  |  |  |
  Chinese | 3000 (80.2) | 888 (81.5) | 1797 (79.5) | 315 (80.8) | 0.016 |
  Malay | 431 (11.5) | 99 (9.1) | 281 (12.4) | 51 (13.1) |  |
  Indian | 215 (5.8) | 72 (6.6) | 122 (5.4) | 21 (5.4) |  |
  Others | 93 (2.5) | 30 (2.8) | 60 (2.7) | 3 (0.8) |  |
 Highest qualification attained, n (%) | |||||
  No formal/primary | 1358 (36.3) | 241 (22.1) | 837 (37.0) | 280 (71.8) | <0.001 |
  Secondary | 1651 (44.2) | 545 (50.0) | 1013 (44.8) | 93 (23.8) |  |
  Post-secondary (non-tertiary) | 202 (5.4) | 84 (7.7) | 114 (5.0) | 4 (1.0) |  |
  Professional diploma | 183 (4.9) | 93 (8.5) | 88 (3.9) | 2 (0.5) |  |
  Tertiary | 227 (6.1) | 94 (8.6) | 131 (5.8) | 2 (0.5) |  |
  Missing | 118 (3.2) | 32 (2.9) | 77 (3.4) | 9 (2.3) |  |
 Housing, n (%) |  |  |  |  |  |
  HDB 1–3 rooms | 912 (24.4) | 192 (17.6) | 566 (25.0) | 154 (39.5) | <0.001 |
  HDB >3 rooms | 2308 (61.7) | 694 (63.7) | 1408 (62.3) | 206 (52.8) |  |
  Private | 462 (12.4) | 193 (17.7) | 247 (10.9) | 22 (5.6) |  |
  Other/missing | 57 (1.5) | 10 (0.9) | 39 (1.7) | 8 (2.1) |  |
 Marital status, n (%) |  |  |  |  |  |
  Married | 2651 (70.9) | 828 (76.0) | 1595 (70.6) | 228 (58.5) | <0.001 |
  Never married | 469 (12.5) | 126 (11.6) | 299 (13.2) | 44 (11.3) |  |
  Widowed | 421 (11.3) | 84 (7.7) | 244 (10.8) | 93 (23.8) |  |
  Separated or divorced | 198 (5.3) | 51 (4.7) | 122 (5.4) | 25 (6.4) |  |
Lifestyle risk factors | |||||
 Smoking, n (%) |  |  |  |  |  |
  No | 3611 (96.6) | 1063 (97.6) | 2179 (96.4) | 369 (94.6) | 0.016 |
  Yes | 128 (3.4) | 26 (2.4) | 81 (3.6) | 21 (5.4) |  |
 Alcohol, n (%) |  |  |  |  |  |
  No | 3633 (97.2) | 1055 (96.9) | 2194 (97.1) | 384 (98.5) | 0.251 |
  Yes | 106 (2.8) | 34 (3.1) | 66 (2.9) | 6 (1.5) |  |
 Physical activity between ages 18 and 30 years, n (%) | |||||
  1 | 264 (7.1) | 70 (6.4) | 158 (7.0) | 36 (9.2) | <0.001 |
  2 | 2517 (67.3) | 673 (61.8) | 1541 (68.2) | 303 (77.7) |  |
  3 | 210 (5.6) | 78 (7.2) | 126 (5.6) | 6 (1.5) |  |
  4 | 455 (12.2) | 146 (13.4) | 279 (12.3) | 30 (7.7) |  |
  5 | 293 (7.8) | 122 (11.2) | 156 (6.9) | 15 (3.8) |  |
Medical risk factors | |||||
 Charlson comorbidity index, n (%) | |||||
  0 | 2549 (68.2) | 780 (71.6) | 1552 (68.7) | 217 (55.6) | <0.001 |
  1 | 852 (22.8) | 216 (19.8) | 520 (23.0) | 116 (29.7) |  |
  >1 | 334 (8.9) | 93 (8.5) | 184 (8.1) | 57 (14.6) |  |
  Missing | 4 (0.1) | 0 (0.0) | 4 (0.2) | 0 (0.0) |  |
 Previous surgery for benign lump, n (%) | |||||
  No | 3301 (88.3) | 896 (82.3) | 2038 (90.2) | 367 (94.1) | <0.001 |
  Yes | 435 (11.6) | 193 (17.7) | 221 (9.8) | 21 (5.4) |  |
  Missing | 3 (0.1) | 0 (0.0) | 1 (0.0) | 2 (0.5) |  |
 Previous gynaecological surgery, n (%) | |||||
  No | 2302 (61.6) | 632 (58.0) | 1414 (62.6) | 256 (65.6) | 0.007 |
  Yes | 1431 (38.3) | 456 (41.9) | 844 (37.3) | 131 (33.6) |  |
  Missing | 6 (0.2) | 1 (0.1) | 2 (0.1) | 3 (0.8) |  |
 Family history of breast cancer, n (%) | |||||
  No | 2759 (73.8) | 760 (69.8) | 1687 (74.6) | 312 (80.0) | <0.001 |
  Yes | 837 (22.4) | 294 (27.0) | 482 (21.3) | 61 (15.6) |  |
  Missing | 143 (3.8) | 35 (3.2) | 91 (4.0) | 17 (4.4) |  |
 Family history of ovarian cancer, n (%) | |||||
  No | 3477 (93.0) | 1017 (93.4) | 2101 (93.0) | 359 (92.1) | 0.797 |
  Yes | 107 (2.9) | 32 (2.9) | 62 (2.7) | 13 (3.3) |  |
  Missing | 155 (4.1) | 40 (3.7) | 97 (4.3) | 18 (4.6) |  |
Reproductive risk factors | |||||
 Age at first full-term pregnancy, n (%) | |||||
  Nulliparous | 725 (19.4) | 200 (18.4) | 462 (20.4) | 63 (16.2) | <0.001 |
  <20 | 217 (5.8) | 45 (4.1) | 118 (5.2) | 54 (13.8) |  |
  20–24 | 808 (21.6) | 209 (19.2) | 497 (22.0) | 102 (26.2) |  |
  25–29 | 1113 (29.8) | 349 (32.0) | 661 (29.2) | 103 (26.4) |  |
  >30 | 853 (22.8) | 283 (26.0) | 510 (22.6) | 60 (15.4) |  |
  Missing | 23 (0.6) | 3 (0.3) | 12 (0.5) | 8 (2.1) |  |
 Parity, n (%) | |||||
  0 | 725 (19.4) | 200 (18.4) | 462 (20.4) | 63 (16.2) | <0.001 |
  1 | 459 (12.3) | 126 (11.6) | 295 (13.1) | 38 (9.7) |  |
  2 | 1296 (34.7) | 442 (40.6) | 762 (33.7) | 92 (23.6) |  |
  ≥3 | 1258 (33.6) | 321 (29.5) | 741 (32.8) | 196 (50.3) |  |
  Missing | 1 (0.0) | 0 (0.0) | 0 (0.0) | 1 (0.3) |  |
 Infertility treatment, n (%) | |||||
  No | 3590 (96.0) | 1028 (94.4) | 2178 (96.4) | 384 (98.5) | <0.001 |
  Yes | 149 (4.0) | 61 (5.6) | 82 (3.6) | 6 (1.5) |  |
 Oral contraception, n (%) | |||||
  No | 2813 (75.2) | 818 (75.1) | 1698 (75.1) | 297 (76.2) | 0.906 |
  Yes | 926 (24.8) | 271 (24.9) | 562 (24.9) | 93 (23.8) |  |
 Hormone replacement treatment, n (%) | |||||
  Never | 3309 (88.5) | 918 (84.3) | 2018 (89.3) | 373 (95.6) | <0.001 |
  Ever | 401 (10.7) | 161 (14.8) | 227 (10.0) | 13 (3.3) |  |
  Missing | 29 (0.8) | 10 (0.9) | 15 (0.7) | 4 (1.0) |  |
 Menopausal status at diagnosis, n (%) | |||||
  Post-menopausal | 3084 (82.5) | 845 (77.6) | 1885 (83.4) | 354 (90.8) | <0.001 |
  Pre-menopausal | 655 (17.5) | 244 (22.4) | 375 (16.6) | 36 (9.2) |  |