Table 1.
Characteristics of Women with Incident Breast Cancer by Rural–Urban Residence at the Time of Diagnosis; Women's Health Initiative (n = 7,120), 1993–2014
| Rural–urban category | ||||
|---|---|---|---|---|
| Characteristics | Total sample N = 7,120 (%) | Urban N = 6,643 (%) | Large rural N = 265 (%) | Small rural N = 212 (%) |
| Sociodemographic/psychosocial | ||||
| Age (years) | ||||
| 50–59 | 2,137 (30) | 1,989 (30) | 75 (28) | 73 (34) |
| 60–69 | 3,336 (47) | 3,109 (47) | 128 (48) | 99 (47) |
| 70–79 | 1,647 (23) | 1,545 (23) | 62 (23) | 40 (19) |
| Race/ethnicity | ||||
| White | 6,192 (87) | 5,732 (86) | 257 (97) | 203 (96) |
| Black | 508 (7) | 495 (7) | 4 (2) | 9 (4) |
| Other | 403 (6) | 399 (6) | 4 (2) | 0 |
| Education | ||||
| None/some HS | 266 (4) | 241 (4) | 11 (4) | 14 (7) |
| HS/GED | 1,094 (15) | 988 (15) | 58 (22) | 48 (23) |
| >HS | 5,700 (80) | 5,359 (81) | 192 (72) | 149 (70) |
| Any insurance | ||||
| No | 221 (3) | 201 (3) | 11 (4) | 9 (4) |
| Yes | 6,843 (96) | 6,389 (96) | 252 (95) | 202 (95) |
| Social strain | ||||
| Median (IQR) | 6 (4,8) | 6 (4,8) | 6 (4,8) | 6 (4,8) |
| (min, max) | (4,20) | (4,20) | (4,16) | (4,16) |
| Social strain | ||||
| Low (≤5) | 3,047 (43) | 2,846 (43) | 117 (44) | 84 (40) |
| High (>5) | 3,935 (55) | 3,667 (55) | 145 (55) | 123 (58) |
| Social support | ||||
| Median (IQR) | 37 (32,43) | 37 (32,42) | 37 (34,53) | 38 (32,44) |
| (min, max) | (9,45) | (9,45) | (12,45) | (17,45) |
| Social support | ||||
| Low (≤37) | 3,553 (50) | 3,321 (50) | 135 (51) | 97 (46) |
| High (>37) | 3,404 (48) | 3,163 (48) | 129 (49) | 112 (53) |
| Health behaviors/history | ||||
| Family history of breast cancer | ||||
| No | 5,083 (71) | 4,768 (72) | 171 (65) | 144 (68) |
| Yes | 1,656 (23) | 1,527 (23) | 72 (27) | 57 (27) |
| Gail risk | ||||
| <1.67% | 3,526 (50) | 3,290 (50) | 116 (44) | 120 (57) |
| ≥1.67% | 3,594 (50) | 3,353 (50) | 149 (56) | 92 (43) |
| Mammogram in past 2 years | ||||
| Yes | 6,065 (85) | 5,678 (85) | 215 (81) | 172 (81) |
| No | 861 (12) | 778 (12) | 44 (17) | 39 (18) |
| WHI trial participation | ||||
| No | 2,853 (40) | 2,660 (40) | 107 (40) | 86 (41) |
| Yes | 4,267 (60) | 3,983 (60) | 158 (60) | 126 (59) |
| WHI study type | ||||
| OS | 4,267 (60) | 3,983 (60) | 158 (60) | 126 (59) |
| E-alone | 228 (4) | 205 (3) | 9 (3) | 14 (7) |
| E+P trial | 436 (6) | 391 (6) | 27 (10) | 18 (8) |
| DM | 1,883 (26) | 1782 (27) | 59 (22) | 42 (20) |
| E-alone/E+P trial + DM | 306 (4) | 282 (4) | 12 (5) | 12 (6) |
| Alcohol | ||||
| Nondrinker | 667 (9) | 578 (9) | 46 (17) | 43 (20) |
| Former drinker | 1,208 (17) | 1,125 (17) | 44 (17) | 39 (18) |
| Current drinker | 5,188 (73) | 4,885 (74) | 175 (66) | 128 (60) |
| Smoking | ||||
| Never smoker | 3,432 (48) | 3,156 (48) | 147 (55) | 129 (61) |
| Past smoker | 3,149 (44) | 2,981 (45) | 104 (39) | 64 (30) |
| Current smoker | 443 (6) | 416 (6) | 10 (4) | 17 (8) |
| Self-rated health | ||||
| Excellent/very good | 4,245 (60) | 3,988 (60) | 150 (57) | 107 (50) |
| Good | 2,264 (32) | 2,088 (31) | 93 (35) | 83 (39) |
| Fair/poor | 575 (8) | 533 (8) | 22 (8) | 20 (9) |
| Physical activity (MET/week) | ||||
| None | 1,030 (14) | 940 (14) | 52 (20) | 38 (18) |
| > 0–3.75 | 987 (14) | 922 (14) | 41 (15) | 24 (11) |
| 3.75–8.75 | 1,411 (20) | 1,316 (20) | 53 (20) | 42 (20) |
| 8.75–17.5 | 1,586 (22) | 1,484 (22) | 62 (23) | 40 (19) |
| ≥17.5 | 1,744 (24) | 1,648 (25) | 41 (15) | 55 (26) |
| Hysterectomy | ||||
| No | 4,398 (62) | 4,120 (62) | 159 (60) | 119 (56) |
| Yes | 2,717 (38) | 2,518 (38) | 106 (40) | 93 (44) |
| Bilateral oophorectomy | ||||
| No | 5,700 (80) | 5,320 (80) | 212 (80) | 168 (79) |
| Yes | 1,277 (18) | 1190 (18) | 47 (18) | 40 (19) |
| Hormone therapy use | ||||
| Never | 2,802 (39) | 2,611 (39) | 97 (37) | 94 (44) |
| Past user | 1,077 (15) | 997 (15) | 42 (16) | 38 (18) |
| Current user <5 years | 841 (12) | 788 (12) | 31 (12) | 22 (10) |
| Current user 5 to <10 years | 826 (12) | 783 (12) | 28 (11) | 15 (7) |
| Current user ≥10 years | 1,569 (22) | 1,459 (22) | 67 (25) | 43 (20) |
| Oral contraceptive use | ||||
| No | 4,235 (59) | 3,972 (60) | 146 (55) | 117 (55) |
| Yes | 2,885 (41) | 2,671 (40) | 119 (45) | 95 (45) |
| Aspirin use | ||||
| No | 5,607 (79) | 5,244 (79) | 201 (76) | 162 (76) |
| Yes | 1,513 (21) | 1,399 (21) | 64 (24) | 50 (24) |
| NSAID use | ||||
| No | 4,744 (67) | 4,453 (67) | 159 (60) | 132 (62) |
| Yes | 2,376 (33) | 2,190 (33) | 106 (40) | 80 (38) |
| Current diabetes | ||||
| No | 6,828 (96) | 6,378 (96) | 252 (95) | 198 (93) |
| Yes | 287 (4) | 261 (4) | 13 (5) | 13 (6) |
| Cholesterol medication use | ||||
| No | 5,748 (81) | 5,369 (81) | 208 (78) | 171 (81) |
| Yes | 939 (13) | 874 (13) | 38 (14) | 27 (13) |
| Myocardial infarction | ||||
| No | 6,970 (98) | 6,504 (98) | 259 (98) | 207 (98) |
| Yes | 147 (2) | 136 (2) | 6 (2) | 5 (2) |
| Angina | ||||
| No | 6,684 (94) | 6,237 (94) | 246 (93) | 201 (95) |
| Yes | 376 (5) | 347 (5) | 19 (7) | 10 (5) |
| Charlson comorbidity index (modified) | ||||
| 0 | 4,178 (59) | 3,921 (59) | 150 (57) | 107 (50) |
| 1+ | 2,775 (39) | 2,564 (39) | 110 (42) | 101 (48) |
DM, dietary modification; E+P, estrogen + progesterone; HS, high school; GED, general equivalency diploma; IQR, interquartile range; MET, metabolic equivalent values; NSAID, nonsteroidal anti-inflammatory drugs; OS, observational study.