Table 1 Malaysian Mammographic Study cohort description by mammography history
Variable | All women | Previous mammogram | First mammogram | P value | |||
|---|---|---|---|---|---|---|---|
N = 1453 | N = 744 | N = 709 | |||||
N | % | N | % | N | % | ||
Demographics | |||||||
Age1a[mean, sd] | 50.0 | 7.0 | 53.0 | 7.0 | 48.0 | 7.0 | <0.001 |
Ethnicity2a | |||||||
Chinese | 1018 | 70.1 | 530 | 71.2 | 488 | 68.8 | 0.194 |
Indian | 223 | 15.4 | 117 | 15.7 | 106 | ||
Malay | 160 | 69 | 9.3 | 91 | 12.8 | ||
Others | 52 | 3.5 | 28 | 3.8 | 24 | 3.4 | |
Education Level2 | |||||||
Primary | 90 | 6.2 | 34 | 4.6 | 56 | 8.1 | 0.006 |
Secondary | 728 | 50.1 | 366 | 49.9 | 362 | 52.3 | |
Tertiary | 608 | 41.8 | 334 | 45.5 | 274 | 39.6 | |
Missing | 27 | 10 | 17 | ||||
Monthly Income (RM)2 | |||||||
Below 5 k | 689 | 47.4 | 325 | 44.1 | 364 | 52.1 | 0.010 |
5 k to 10 k | 470 | 32.4 | 260 | 35.3 | 210 | ||
Above 10 k | 277 | 19.1 | 152 | 20.6 | 125 | 17.9 | |
Missing | 20 | 10 | 10 | ||||
Hormonal | |||||||
Endogenous | |||||||
Age at menarche1a[mean, sd] | 13.0 | 1.0 | 13.0 | 1.0 | 13.0 | 1.0 | 0.626 |
Missing | 10 | 5 | 5 | ||||
Menopausal status2 | |||||||
Pre/perimenopausal | 783 | 53.9 | 299 | 40.2 | 484 | 68.6 | <0.001 |
Post-menopausal | 667 | 45.9 | 445 | 59.8 | 222 | 31.4 | |
Missing | 3 | 0 | 3 | ||||
Parity2 | |||||||
Nulliparous | 229 | 15.8 | 104 | 125 | 17.6 | 0.057 | |
Parous | 1224 | 84.2 | 640 | 584 | 82.4 | ||
Age at first live births1a[mean, sd] | 28.0 | 5.0 | 28.0 | 5.0 | 27.0 | 5.0 | 0.001 |
Missing | 230 | 105 | 125 | ||||
Exogenous | |||||||
Oral contraceptive usage status2 | |||||||
Never | 1004 | 69.1 | 508 | 68.5 | 496 | 70.4 | 0.435 |
Ever used | 443 | 30.5 | 234 | 31.5 | 209 | 29.6 | |
Missing | 6 | 2 | 4 | ||||
Hormone replacement therapy | |||||||
(HRT) status2 | |||||||
Never | 1306 | 89.9 | 627 | 84.6 | 679 | <0.001 | |
Ever used | 142 | 9.8 | 114 | 15.4 | 28 | ||
Missing | 5 | 3 | 2 | ||||
Medical history | |||||||
Family history of breast cancer2a | |||||||
No | 1301 | 89.5 | 646 | 86.8 | 655 | 92.4 | <0.001 |
Yes | 152 | 10.5 | 98 | 13.2 | 54 | 7.6 | |
Previous breast biopsy status2a | |||||||
No | 1305 | 89.8 | 676 | 91.5 | 629 | 89.6 | 0.224 |
Yes | 136 | 9.4 | 63 | 8.5 | 73 | 10.4 | |
Missing | 12 | 5 | 7 | ||||
Gynaecological surgery2 | |||||||
No | 1143 | 78.7 | 578 | 79.7 | 565 | 79.7 | 0.352 |
Yes | 310 | 21.3 | 166 | 22.3 | 144 | 20.3 | |
Sterilisation | 103 | 7.1 | 52 | 51 | 7.2 | ||
Oopherectomy | 33 | 2.3 | 21 | 2.8 | 12 | 1.7 | |
Hysterectomy | 82 | 5.6 | 40 | 5.4 | 42 | 5.9 | |
Total Hysterectomy/TAHBSO | 69 | 4.8 | 37 | 32 | 4.5 | ||
Salpingectomy/salpingostomy | 23 | 1.6 | 16 | 2.1 | 7 | ||
Body Mass Index (BMI)2 | |||||||
Underweight | 48 | 3.3 | 16 | 32 | 4.5 | 0.030 | |
Normal weight | 812 | 55.9 | 425 | 57.1 | 387 | ||
Overweight | 576 | 39.6 | 292 | 284 | 40.0 | ||
Missing | 17 | 11 | 6 | ||||
Diabetes status2 | |||||||
No | 1335 | 91.9 | 673 | 91.1 | 662 | 93.8 | 0.050 |
Yes | 110 | 7.6 | 66 | 8.9 | 44 | 6.2 | |
Missing | 8 | 5 | 3 | ||||
Smoking status2 | |||||||
Never | 1312 | 90.3 | 671 | 90.2 | 641 | 90.4 | 0.887 |
Ever smoked | 141 | 9.7 | 73 | 9.8 | 68 | 9.6 | |