Table 3.
Odds ratios (OR) and 95% confidence intervals (CI) of having dense breasts (BI-RADS category 3 or 4 vs. 1 or 2) in association with lifestyle and demographic factors in Vietnamese American women*
| Dense (BI-RADS 3 or 4) N (%) | Non-dense (BI-RADS 1 or 2) N (%) | Age and BMI- adjusted OR (95% Cl) | P-value | Multivariable OR (95% Cl)¶ | P-value | |
|---|---|---|---|---|---|---|
| Age (per year) | Mean: 53.7 (SD: 7.5) | Mean: 56.3 (SD: 7.0) | 0.96 (0.93–0.98) | 0.002 | 0.95 (0.91–0.99) | 0.024 |
| BMI (per Kg/m2) | Mean: 22.5 (SD: 2.9) | Mean: 23.4 (SD: 3.1) | 0.90 (0.84–0.97) | 0.005 | 0.92 (0.86–0.99) | 0.034 |
| Education | ||||||
| <6 years | 8 (4%) | 14 (9%) | 1 (Ref) | 1 (Ref) | ||
| 6–12 years | 140 (65%) | 112 (69%) | 1.58 (0.62–3.98) | 1.14 (0.43–3.00) | ||
| 13+ years | 69 (32%) | 37 (23%) | 2.44 (0.92–6.50) | 1.48 (0.52–4.17) | ||
| Trend (Per category) | 0.032 | 0.29 | ||||
| Age at menarche (years) | ||||||
| ≤12 | 30 (14%) | 23 (14%) | 1 (Ref) | 1 (Ref) | ||
| 13–14 | 76 (35%) | 72 (44%) | 0.83 (0.44–1.59) | 0.86 (0.44–1.66) | ||
| 15 | 44 (20%) | 20 (12%) | 1.52 (0.70–3.31) | 1.64 (0.73–3.66) | ||
| 16+ | 67 (31%) | 48 (29%) | 1.01 (0.51–1.98) | 1.27 (0.63–2.58) | ||
| 0.52 | 0.16 | |||||
| Menopausal status | ||||||
| Premenopausal | 85 (39%) | 45 (28%) | 1 (Ref) | 1 (Ref) | ||
| Postmenopausal | 132 (61%) | 118 (72%) | 1.00 (0.52–1.91) | 0.99 | 1.05 (0.54–2.06) | 0.89 |
| Hormone therapy (among postmenopausal women) | ||||||
| Never | 122 (92%) | 111 (94%) | 1 (Ref) | 1 (Ref) | ||
| Ever | 10 (8%) | 7 (6%) | 1.59 (0.54–4.67) | 0.40 | 1.19 (0.39–3.62) | 0.76 |
| Number of delivery | ||||||
| 0 | 26 (12%) | 15 (9%) | 1 (Ref) | 1 (Ref) | ||
| 1–2 | 134 (62%) | 72 (44%) | 0.99 (0.49–2.02) | 1.07 (0.52–2.22) | ||
| 3–4 | 47 (22%) | 50 (31%) | 0.56 (0.26–1.20) | 0.62 (0.28–1.36) | ||
| 5+ | 10 (5%) | 26 (16%) | 0.28 (1.10–0.75) | 0.35 (0.12–0.97) | ||
| Trend P (Per category) | 0.001 | 0.006 | ||||
| Age at first birth (among parous women; years) | ||||||
| <30 | 113 (59%) | 105 (71%) | 1 (Ref) | 1 (Ref) | ||
| 30+ | 78 (41%) | 43 (30%) | 1.56 (0.98–2.50) | 0.063 | 1.14 (0.67–1.92) | 0.63 |
| Duration of breastfeeding (among parous women) | ||||||
| Did not breastfeed | 58 (30%) | 29 (19%) | 1 (Ref) | 1 (Ref) | ||
| < 1 year | 64 (34%) | 28 (19%) | 1.16 (0.61–2.21) | 1.27 (0.66–2.44) | ||
| 1 – <2 | 27 (14%) | 26 (17%) | 0.57 (0.28–1.15) | 0.78 (0.37–1.65) | ||
| 2+ | 42 (22%) | 65 (44%) | 0.39 (0.21–0.72) | 0.69 (0.34–1.40) | ||
| Trend P (Per category) | 0.0003 | 0.19 | ||||
| Length of US residence (years) | ||||||
| ≤5 | 14 (6%) | 21 (13%) | 1 (Ref) | 1 (Ref) | ||
| 6–10 | 19 (9%) | 18 (11%) | 1.62 (0.62–4.25) | 1.51 (0.56–4.08) | ||
| 11–20 | 38 (18%) | 33 (21%) | 1.73 (0.74–4.03) | 1.49 (0.62–3.55) | ||
| 21–30 | 101 (47%) | 61 (37%) | 2.82 (1.30–6.11) | 2.38 (1.07–5.29) | ||
| 31+ | 45 (21%) | 30 (18%) | 3.17 (1.33–7.56) | 2.87 (1.16–7.09) | ||
| Trend P (Per category) | 0.002 | 0.006 | ||||
| Age at US migration (years) | ||||||
| 40+ | 41 (19%) | 63 (39%) | 1 (Ref) | 1 (Ref) | ||
| 30–39 | 65 (30%) | 44 (27%) | 2.11 (1.20–3.69) | 1.72 (0.96–3.07) | ||
| <30 | 111 (51%) | 56 (34%) | 2.58 (1.50–4.43) | 2.48 (1.43–4.32) | ||
| Trend (Per category) | 0.001 | 0.001 | ||||
| English proficiency | ||||||
| Speak not very well or not at all | 57 (26%) | 55 (34%) | 1 (Ref) | 1 (Ref) | ||
| Speak somewhat well | 139 (64%) | 94 (58%) | 1.35 (0.85–2.15) | 1.00 (0.60–1.66) | ||
| Fluent or speak pretty well | 21 (10%) | 14 (9%) | 1.41 (0.64–3.11) | 0.88 (0.37–2.08) | ||
| Trend (Per category) | 0.23 | 0.82 |
¶
Odds ratios and 95% confidence intervals were estimated by using multivariable logistic regression models. All variables presented in the table were adjusted for age, BMI, education, menopausal status, hormone therapy, number of delivery, and length of US residence (except for analysis of age at US migration).