Table 1.
Characteristics of Study Participants
| Variable | All (N = 2,951) | STRATUS (N = 2,450) | Volpara (N = 2,257) | STRATUS vs. Volpara | |||
|---|---|---|---|---|---|---|---|
| Mean (SD) or N (%) | Mean (SD) or N (%) | Mean (SD) or N (%) | P value | ||||
| Age at mammography (years) | 53.2 | (8.2) | 52.7 | (8.1) | 54.0 | (8.4) | <0.001 |
| BMI (kg/m2) | 25.2 | (4.6) | 25.1 | (4.5) | 25.5 | (4.7) | 0.005 |
| Menopausal status | <0.001 | ||||||
| Premenopausal | 1,203 | (40.8) | 1,047 | (42.7) | 851 | (37.7) | |
| Postmenopausal | 1,748 | (59.2) | 1,403 | (57.3) | 1,406 | (62.3) | |
| Parity status | 0.176 | ||||||
| Nulliparous | 500 | (16.9) | 400 | (16.3) | 402 | (17.8) | |
| Parous | 2,451 | (83.1) | 2050 | (83.7) | 1,855 | (82.2) | |
| Number of live birthsa | 2.8 | (1.2) | 2.3 | (1.5) | 2.3 | (1.5) | 0.949 |
| Age at 1st child birth (years)a | 27.3 | (4.7) | 27.4 | 4(.7) | 27.2 | (4.7) | 0.118 |
| Ethnicityb | <0.001 | ||||||
| Chinese | 1,682 | (57.0) | 1,476 | (60.2) | 1,214 | (53.8) | |
| Indian | 648 | (22.0) | 453 | (18.5) | 529 | (23.4) | |
| Malay | 621 | (21.0) | 521 | (21.3) | 514 | (22.8) | |
| Recruitment centre | <0.001 | ||||||
| Subang Jaya Medical Centre (SJMC) | 1,668 | (56.5) | 1,668 | (68.1) | 988 | (43.8) | |
| University Malaya Medical Centre (UMMC) | 1,283 | (43.5) | 782 | (31.9) | 1,269 | (56.2) | |
| Mammogram system | <0.001 | ||||||
| Hologic | 2,582 | (87.5) | 2,338 | (95.4) | 1,892 | (83.8) | |
| GE | 224 | (7.6) | 112 | (4.6) | 220 | (9.7) | |
| Siemens | 145 | (4.9) | 0 | (0) | 145 | (6.4) | |
a
Among parous women only.
b
Self-reported ethnicity.