Table 4 Associations between sociodemographic factors and mammography behaviour
| Â | Screeners, n=1089 | Non-screeners, n=2260 | Unaware, n=390 | |||||
|---|---|---|---|---|---|---|---|---|
N | Â | N | OR (95% CI) | P | N | OR (95% CI) | P | |
Sociodemographic factors | ||||||||
 Age at diagnosis (categorical) | ||||||||
  50–59 | 610 | 1.00 (reference) | 1084 |  |  | 106 |  |  |
  ≥60 | 479 |  | 1176 | 1.36 (1.18–1.58) | <0.001 | 284 | 3.60 (2.79–4.66) | <0.001 |
 Ethnicity | ||||||||
  Chinese | 888 | 1.00 (reference) | 1797 |  |  | 315 |  |  |
  Malay | 99 |  | 281 | 1.42 (1.11–1.82) | 0.005 | 51 | 1.89 (1.29–2.77) | 0.001 |
  Indian | 72 |  | 122 | 0.85 (0.62–1.15) | 0.285 | 21 | 0.97 (0.58–1.63) | 0.906 |
  Others | 30 |  | 60 | 0.94 (0.60–1.48) | 0.79 | 3 | 0.24 (0.07–0.83) | 0.024 |
 Highest qualification attained | ||||||||
  No formal/primary | 241 |  | 837 | 1.76 (1.46–2.11) | <0.001 | 280 | 5.04 (3.77–6.75) | <0.001 |
  Secondary | 545 | 1.00 (reference) | 1013 |  |  | 93 |  |  |
  Post-secondary (non-tertiary) | 84 |  | 114 | 0.75 (0.55–1.01) | 0.062 | 4 | 0.30 (0.11–0.83) | 0.021 |
  Professional diploma | 93 |  | 88 | 0.51 (0.37–0.70) | <0.001 | 2 | 0.15 (0.04–0.63) | 0.01 |
  Tertiary | 94 |  | 131 | 0.75 (0.56–1.00) | 0.053 | 2 | 0.14 (0.03–0.58) | 0.007 |
  Missing | 32 |  | 77 |  |  | 9 |  |  |
 Housing | ||||||||
  HDB 1–3 rooms | 192 |  | 566 | 1.43 (1.18–1.73) | <0.001 | 154 | 2.33 (1.77–3.07) | <0.001 |
  HDB >3 rooms | 694 | 1.00 (reference) | 1408 |  |  | 206 |  |  |
  Private | 193 |  | 247 | 0.60 (0.48–0.74) | <0.001 | 22 | 0.28 (0.17–0.45) | <0.001 |
  Others/missing | 10 |  | 39 |  |  | 8 |  |  |
 Marital status | ||||||||
  Married | 828 | 1.00 (reference) | 1595 |  |  | 228 |  |  |
  Never married | 126 |  | 299 | 1.25 (0.99–1.57) | 0.057 | 44 | 1.18 (0.80–1.73) | 0.41 |
  Widowed | 84 |  | 244 | 1.26 (0.95–1.67) | 0.106 | 93 | 1.85 (1.28–2.69) | 0.001 |
  Separated/divorced | 51 |  | 122 | 1.22 (0.86–1.71) | 0.261 | 25 | 1.57 (0.93–2.65) | 0.09 |
Lifestyle risk factors | ||||||||
 Smoking | ||||||||
  No | 1063 | 1.00 (reference) | 2179 |  |  | 369 |  |  |
  Yes | 26 |  | 81 | 1.59 (1.01–2.50) | 0.045 | 21 | 2.85 (1.53–5.32) | <0.001 |
 Alcohol |  |  |  |  |  |  |  |  |
  No | 1055 | 1.00 (reference) | 2194 |  |  | 384 |  |  |
  Yes | 34 |  | 66 | 1.00 (0.66–1.53) | 0.99 | 6 | 0.63 (0.26–1.55) | 0.313 |
 Physical activity between 18 and 30 | ||||||||
  1 | 70 |  | 158 | 0.90 (0.65–1.25) | 0.543 | 36 | 0.80 (0.48–1.33) | 0.397 |
  2 | 673 | 1.00 (reference) | 1541 |  |  | 303 |  |  |
  3 | 78 |  | 126 | 0.75 (0.55–1.02) | 0.068 | 6 | 0.17 (0.07–0.42) | <0.001 |
  4 | 146 |  | 279 | 0.89 (0.71–1.11) | 0.302 | 30 | 0.49 (0.32–0.76) | 0.001 |
  5 | 122 |  | 156 | 0.52 (0.40–0.68) | <0.001 | 15 | 0.30 (0.17–0.53) | <0.001 |
Medical risk factors | ||||||||
 Charlson comorbidity index | ||||||||
  0 | 780 | 1.00 (reference) | 1552 |  |  | 217 |  |  |
  1 | 216 |  | 520 | 1.14 (0.95–1.38) | 0.154 | 116 | 1.48 (1.11–1.97) | 0.007 |
  >1 | 93 |  | 184 | 0.94 (0.71–1.22) | 0.626 | 57 | 1.57 (1.07–2.31) | 0.021 |
  Missing | 0 |  | 4 |  |  | 0 |  |  |
 Previous surgery for benign lump | ||||||||
  No | 896 | 1.00 (reference) | 2038 |  |  | 367 |  |  |
  Yes | 193 |  | 221 | 0.50 (0.41–0.62) | <0.001 | 21 | 0.28 (0.17–0.45) | <0.001 |
  Missing | 0 |  | 1 |  |  | 2 |  |  |
 Previous gynaecological surgery | ||||||||
  No | 632 | 1.00 (reference) | 1414 |  |  | 256 |  |  |
  Yes | 456 |  | 844 | 0.79 (0.68–0.92) | 0.002 | 131 | 0.64 (0.50–0.83) | <0.001 |
  Missing | 1 |  | 2 |  |  | 3 |  |  |
 Family history of breast cancer | ||||||||
  No | 760 | 1.00 (reference) | 1687 |  |  | 312 |  |  |
  Yes | 294 |  | 482 | 0.74 (0.62–0.87) | <0.001 | 61 | 0.54 (0.39–0.74) | <0.001 |
  Missing | 35 |  | 91 |  |  | 17 |  |  |
 Family history of ovarian cancer | ||||||||
  No | 1017 | 1.00 (reference) | 2101 |  |  | 359 |  |  |
  Yes | 32 |  | 62 | 0.98 (0.63–1.52) | 0.918 | 13 | 1.37 (0.69–2.72) | 0.369 |
  Missing | 40 |  | 97 |  |  | 18 |  |  |
Reproductive risk factors | ||||||||
 Age at first full-term pregnancy | ||||||||
  Nulliparous | 200 |  | 462 | 1.27 (1.03–1.57) | 0.028 | 63 | 1.18 (0.81–1.71) | 0.387 |
  <20 | 45 |  | 118 | 1.31 (0.90–1.90) | 0.153 | 54 | 3.19 (1.98–5.13) | <0.001 |
  20–24 | 209 |  | 497 | 1.20 (0.97–1.49) | 0.085 | 102 | 1.42 (1.01–1.99) | 0.042 |
  25–29 | 349 | 1.00 (reference) | 661 |  |  | 103 |  |  |
  >30 | 283 |  | 510 | 0.99 (0.81–1.20) | 0.908 | 60 | 0.86 (0.59–1.24) | 0.411 |
  Missing | 3 |  | 12 |  |  | 8 |  |  |
 Parity | ||||||||
  0 | 200 |  | 462 | 1.37 (1.11–1.68) | 0.003 | 63 | 1.45 (1.00–2.11) | 0.049 |
  1 | 126 |  | 295 | 1.39 (1.09–1.77) | 0.008 | 38 | 1.40 (0.90–2.17) | 0.136 |
  2 | 442 | 1.00 (reference) | 762 |  |  | 92 |  |  |
  ≥3 | 321 |  | 741 | 1.25 (1.04–1.50) | 0.015 | 196 | 2.06 (1.52–2.78) | <0.001 |
 Missing | 0 |  | 0 |  |  | 1 |  |  |
 Infertility treatment | ||||||||
  No | 1028 | 1.00 (reference) | 2178 |  |  | 384 |  |  |
  Yes | 61 |  | 82 | 0.72 (0.51–1.02) | 0.068 | 6 | 0.47 (0.20–1.10) | 0.083 |
 Oral contraception | ||||||||
  No | 818 | 1.00 (reference) | 1698 |  |  | 297 |  |  |
  Yes | 271 |  | 562 | 0.98 (0.82–1.16) | 0.781 | 93 | 0.82 (0.62–1.10) | 0.185 |
 Hormone replacement treatment | ||||||||
  Never | 918 | 1.00 (reference) | 2018 |  |  | 373 |  |  |
  Ever | 161 |  | 227 | 0.59 (0.47–0.74) | <0.001 | 13 | 0.14 (0.08–0.26) | <0.001 |
  Missing | 10 |  | 15 |  |  | 4 |  |  |
 Menopausal status at diagnosis | ||||||||
  Post-menopausal | 845 | 1.00 (reference) | 1885 |  |  | 354 |  |  |
  Pre-menopausal | 244 |  | 375 | 0.94 (0.76–1.17) | 0.608 | 36 | 1.27 (0.82–1.95) | 0.287 |