Selected characteristics among controls who were never/former oral contraceptive users and recent oral contraceptive users
| . | . | . | Medical record review subseta . | |
|---|---|---|---|---|
| . | Combined OC useb . | Combined OC useb . | ||
| . | Never/former use (n = 19,953) . | Recent use (n = 1,999) . | Never/former use (n = 579) . | Recent use (n = 103) . |
| . | n (%) . | n (%) . | n (%) . | n (%) . |
| Agec, y | ||||
| 19–29 | 132 (0.7) | 65 (3.3) | 13 (2.3) | 5 (4.9) |
| 30–34 | 839 (4.2) | 302 (15.1) | 49 (8.5) | 20 (19.4) |
| 35–39 | 2,518 (12.6) | 426 (21.3) | 140 (24.2) | 33 (32.0) |
| 40–44 | 6,185 (31.0) | 549 (27.5) | 377 (65.1) | 45 (43.7) |
| 45–50 | 10,279 (51.5) | 657 (32.9) | 0 (0.0) | 0 (0.0) |
| Race | ||||
| White | 11,519 (79.8) | 1,209 (82.6) | 311 (76.8) | 53 (79.1) |
| Asian | 1,490 (10.3) | 121 (8.3) | 51 (12.6) | 7 (10.4) |
| Black | 757 (5.2) | 69 (4.7) | 27 (6.7) | 4 (6.0) |
| Other | 674 (4.7) | 65 (4.4) | 16 (4.0) | 3 (4.5) |
| Missing | 5,513 | 535 | 174 | 36 |
| Ethnicity | ||||
| Non-Hispanic | 15,083 (95.1) | 1,428 (94.4) | 401 (95.0) | 63 (92.6) |
| Hispanic | 775 (4.9) | 85 (5.6) | 21 (5.0) | 5 (7.4) |
| Missing | 4,095 | 486 | 157 | 35 |
| Body mass index (kg/m2, available for reference dates from June 1998 and later)d | ||||
| <25 | 2,771 (40.9) | 425 (46.8) | 148 (40.4) | 40 (48.8) |
| 25.0–29.9 | 1,862 (27.5) | 235 (25.9) | 100 (27.3) | 22 (26.8) |
| 30+ | 2,140 (31.6) | 249 (27.4) | 118 (32.2) | 20 (24.4) |
| Missing | 2,869 | 385 | 38 | 4 |
| Recent screening mammogram (within 18 months before reference date, available for women ≥40 years of age with reference dates from June 1998 and later)e | ||||
| No | 5,580 (71.2) | 507 (62.5) | 186 (75.6) | 27 (77.1) |
| Yes | 2,256 (28.8) | 304 (37.5) | 60 (24.4) | 8 (22.9) |
| Parous | ||||
| No | — | — | 126 (24.7) | 42 (42.4) |
| Yes | — | — | 384 (75.3) | 57 (57.6) |
| Missing | 69 | 4 | ||
| First-degree family history of breast cancer (includes mother, sisters, and daughters) | ||||
| No | — | — | 416 (91.0) | 81 (94.2) |
| Yes | — | — | 41 (9.0) | 5 (5.8) |
| Missing | 122 | 17 | ||
| First-degree family history of ovarian cancer (includes mother, sisters, and daughters) | ||||
| No | — | — | 399 (98.0) | 76 (96.2) |
| Yes | — | — | 8 (2.0) | 3 (3.8) |
| Missing | 172 | 24 | ||
| . | . | . | Medical record review subseta . | |
|---|---|---|---|---|
| . | Combined OC useb . | Combined OC useb . | ||
| . | Never/former use (n = 19,953) . | Recent use (n = 1,999) . | Never/former use (n = 579) . | Recent use (n = 103) . |
| . | n (%) . | n (%) . | n (%) . | n (%) . |
| Agec, y | ||||
| 19–29 | 132 (0.7) | 65 (3.3) | 13 (2.3) | 5 (4.9) |
| 30–34 | 839 (4.2) | 302 (15.1) | 49 (8.5) | 20 (19.4) |
| 35–39 | 2,518 (12.6) | 426 (21.3) | 140 (24.2) | 33 (32.0) |
| 40–44 | 6,185 (31.0) | 549 (27.5) | 377 (65.1) | 45 (43.7) |
| 45–50 | 10,279 (51.5) | 657 (32.9) | 0 (0.0) | 0 (0.0) |
| Race | ||||
| White | 11,519 (79.8) | 1,209 (82.6) | 311 (76.8) | 53 (79.1) |
| Asian | 1,490 (10.3) | 121 (8.3) | 51 (12.6) | 7 (10.4) |
| Black | 757 (5.2) | 69 (4.7) | 27 (6.7) | 4 (6.0) |
| Other | 674 (4.7) | 65 (4.4) | 16 (4.0) | 3 (4.5) |
| Missing | 5,513 | 535 | 174 | 36 |
| Ethnicity | ||||
| Non-Hispanic | 15,083 (95.1) | 1,428 (94.4) | 401 (95.0) | 63 (92.6) |
| Hispanic | 775 (4.9) | 85 (5.6) | 21 (5.0) | 5 (7.4) |
| Missing | 4,095 | 486 | 157 | 35 |
| Body mass index (kg/m2, available for reference dates from June 1998 and later)d | ||||
| <25 | 2,771 (40.9) | 425 (46.8) | 148 (40.4) | 40 (48.8) |
| 25.0–29.9 | 1,862 (27.5) | 235 (25.9) | 100 (27.3) | 22 (26.8) |
| 30+ | 2,140 (31.6) | 249 (27.4) | 118 (32.2) | 20 (24.4) |
| Missing | 2,869 | 385 | 38 | 4 |
| Recent screening mammogram (within 18 months before reference date, available for women ≥40 years of age with reference dates from June 1998 and later)e | ||||
| No | 5,580 (71.2) | 507 (62.5) | 186 (75.6) | 27 (77.1) |
| Yes | 2,256 (28.8) | 304 (37.5) | 60 (24.4) | 8 (22.9) |
| Parous | ||||
| No | — | — | 126 (24.7) | 42 (42.4) |
| Yes | — | — | 384 (75.3) | 57 (57.6) |
| Missing | 69 | 4 | ||
| First-degree family history of breast cancer (includes mother, sisters, and daughters) | ||||
| No | — | — | 416 (91.0) | 81 (94.2) |
| Yes | — | — | 41 (9.0) | 5 (5.8) |
| Missing | 122 | 17 | ||
| First-degree family history of ovarian cancer (includes mother, sisters, and daughters) | ||||
| No | — | — | 399 (98.0) | 76 (96.2) |
| Yes | — | — | 8 (2.0) | 3 (3.8) |
| Missing | 172 | 24 | ||
Abbreviation: OC, oral contraceptive.
aIncludes up to two of the controls matched to all cases ages 20–44 years with reference dates from May 1995 and later. Information came from medical records and breast cancer screening questionnaires.
bRecent use is defined as filling at least one combined oral contraceptive script in the year before reference date.
cSome controls are outside of the 20–49 age range due to expanded matching criteria.
dBody mass index before reference date (closest to 1 year prior) from medical records and breast cancer screening questionnaires.
eAmong women with 18+ months of enrollment before reference date. Excludes symptomatic and diagnostic mammograms. Mammography data were complete for all women with reference dates from June 1998 and later.