Table 1.
Baseline characteristics and univariable and multivariable logistic regression analyses evaluating factors associated with initiation of chemoprevention
| Characteristic | Total (n) | Chemoprevention initiated, n (column %) |
Univariable analysis | Multivariable analysis | |||
|---|---|---|---|---|---|---|---|
| No n = 510 |
Yes n = 150 |
OR (95% CI) | p-value | OR (95% CI) | p-value | ||
| Age | < 0.001 | ||||||
| 35–40 | 19 | 17 (3) | 2 (1) | 0.3 (0.1–1.5) | 0.16 | 0.4 (0.1–1.9) | 0.24 |
| 41–50 | 176 | 123 (24) | 53 (36) | 1.2 (0.8–1.9) | 0.31 | 1.4 (0.7–2.9) | 0.32 |
| 51–60 | 272 | 202 (40) | 70 (47) | Ref | – | Ref | – |
| 61–70 | 141 | 121 (24) | 20 (13) | 0.5 (0.3–0.8) | 0.008 | 0.5 (0.3–0.8) | 0.008 |
| > 70 | 52 | 47 (9) | 5 (3) | 0.3 (0.1–0.8) | 0.02 | 0.3 (0.1–0.8) | 0.01 |
| Race | 0.08 | ||||||
| White | 538 | 412 (81) | 126 (84) | Ref | – | Ref | – |
| Black/African American | 26 | 24 (5) | 2 (1) | 0.3 (0.1–1.2) | 0.08 | 0.3 (0.1–1.2) | 0.08 |
| Other | 81 | 59 (12) | 22 (15) | 1.2 (0.7–2.1) | 0.46 | 1.2 (0.7–2.1) | 0.47 |
| Unknown | 15 | 15 (3) | 0 (0) | No events | – | No events | – |
| Hispanic ethnicity | 0.61 | ||||||
| No | 580 | 445 (87) | 135 (90) | Ref | – | ||
| Yes | 57 | 42 (8) | 15 (10) | 1.2 (0.6–2.2) | 0.61 | ||
| Unknown | 23 | 23 (5) | 0 (0) | No events | – | ||
| Ashkenazi Jewish | 0.15 | ||||||
| No | 538 | 410 (80) | 128 (85) | Ref | – | ||
| Yes | 62 | 48 (9) | 14 (9) | 0.9 (0.5–1.7) | 0.83 | ||
| Unknown | 60 | 52 (10) | 8 (5) | 0.5 (0.2–1.0) | 0.07 | ||
| Menopausal status at first visit | 0.09 | ||||||
| Pre/Peri | 183 | 133 (26) | 50 (33) | Ref | – | Ref | – |
| Post | 477 | 377 (74) | 100 (67) | 0.7 (0.5–1.0) | 0.08 | 1.2 (0.6–2.5) | 0.56 |
| Alcohol use | 0.71 | ||||||
| Never/rarely | 356 | 278 (55) | 78 (52) | Ref | – | ||
| 1–4 drinks/week | 173 | 130 (25) | 43 (28) | 1.2 (0.8–1.8) | 0.45 | ||
| 5–9 drinks/week | 94 | 75 (15) | 19 (13) | 0.9 (0.5–1.6) | 0.72 | ||
| > 10 drinks/week | 14 | 9 (2) | 5 (3) | 2.0 (0.6–6.1) | 0.23 | ||
| Unknown | 23 | 18 (4) | 5 (3) | 1.0 (0.4–2.8) | 0.99 | ||
| BMI | 0.34 | ||||||
| Under/Normal (< 25) | 247 | 188 (37) | 59 (39) | Ref | – | ||
| Overweight (25–29.9) | 220 | 165 (32) | 55 (37) | 1.1 (0.7–1.6) | 0.78 | ||
| Obese (> 30.0) | 187 | 151 (30) | 36 (24) | 0.8 (0.5–1.2) | 0.25 | ||
| Unknown | 6 | 6 (1) | 0 (0) | No events | – | ||
| Smoking | 0.07 | ||||||
| Never | 431 | 324 (64) | 107 (71) | Ref | – | Ref | |
| Former | 185 | 147 (29) | 38 (25) | 0.8 (0.5–1.2) | 0.25 | 0.9 (0.6–1.4) | 0.67 |
| Current | 20 | 19 (4) | 1 (1) | 0.2 (0.0–1.2) | 0.08 | 0.1 (0.0–1.1) | 0.07 |
| Unknown | 24 | 20 (4) | 4 (3) | 0.6 (0.2–1.8) | 0.37 | 1.3 (0.4–4.3) | 0.72 |
| Breast density on mammogram | 0.28 | ||||||
| 1 or 2 | 208 | 166 (32) | 42 (28) | Ref | – | ||
| 3 or 4 | 391 | 294 (58) | 97 (65) | 1.3 (0.9–2.0) | 0.20 | ||
| Unknown | 61 | 51 (10) | 11 (7) | 0.9 (0.4–1.8) | 0.71 | ||
| Family history of breast cancer | 0.04 | ||||||
| No | 286 | 232 (45) | 54 (36) | Ref | – | Ref | |
| Yes | 374 | 278 (55) | 96 (64) | 1.5 (1.0–2.2) | 0.04 | 1.6 (1.1–2.3) | 0.03 |
| Genetic risk (defined as BRCAPRO or Myriad score > 5%) | 0.74 | ||||||
| No | 560 | 434 (85) | 126 (84) | Ref | – | ||
| Yes | 100 | 76 (15) | 24 (16) | 1.1 (0.7–1.8) | 0.74 | ||
| HRL type | 0.17 | ||||||
| Atypical hyperplasia | 520 | 408 (80) | 112 (75) | Ref | – | ||
| LCIS | 140 | 102 (20) | 38 (25) | 1.4 (0.9–2.1) | 0.16 | ||
P-values are in bold represent association between baseline characteristic and initiation of chemoprevention for the univarable analysis. (this is distinct from p-values representing OR for a given row)
BMI body mass index; CI confidence interval; OR odds ratio; LCIS lobular carcinoma in situ