Table 1.
Baseline demographic and clinical characteristics of participating women.
| Whole cohort (n = 1553) | Development set (n = 1332) | Validation set (n = 221) | P valuec | |
|---|---|---|---|---|
| Patient variables | ||||
| Agee, mean (SD), years | 50.19 (9.98) | 50.22 (10.10) | 49.99 (9.22) | 0.732# |
| BMIe, mean (SD), kg/m2 | 26.49 (5.39) | 26.61 (5.48) | 25.72 (4.76) | 0.012# |
| Diabetese, no (%) | 0.577a | |||
| No, no. (%) | 1482 (95.4) | 1269 (95.3) | 213 (96.4) | |
| Yes, no. (%) | 71 (4.6) | 63 (4.7) | 8 (3.6) | |
| Smokere | ||||
| Never, no. (%) | 1032 (66.5) | 888 (66.7) | 144 (65.2) | 0.726a |
| Previous, no. (%) | 482 (31.0) | 409 (30.7) | 73 (33.0) | 0.534a |
| Current, no. (%) | 26 (1.7) | 24 (1.8) | 2 (0.9) | 0.498a |
| Unknown, no. (%) | 13 (0.8) | 11 (0.8) | 2 (0.9) | 1 |
| Pre-operative patient-reported outcome data | ||||
| BREAST-Q satisfaction with breaste, mean (SD), 0–100 | 59.96 (22.12) | 59.76 (22.10) | 61.33 (22.22) | 0.330b |
| BREAST-Q psychosocial well-beinge, mean (SD), 0–100 | 69.57 (18.08) | 69.49 (18.13) | 70.04 (17.81) | 0.673b |
| BREAST-Q physical well-being chest and upper bodye, mean (SD), 0–100 | 78.87 (14.55) | 78.50 (14.56) | 81.10 (14.31) | 0.013b |
| BREAST-Q physical well-being abdomen, mean (SD)e, 0–100 | 89.53 (13.46) | 89.27 (14.56) | 91.11 (11.37) | 0.033b |
| BREAST-Q sexual well-beinge, mean (SD), 0–100 | 54.90 (20.73) | 55.03 (20.59) | 54.11 (21.55) | 0.562b |
| Clinical variables | ||||
| Radiatione | ||||
| After reconstruction, no. (%) | 293 (18.9) | 252 (18.9) | 41 (18.6) | 0.971a |
| Before reconstruction, no. (%) | 220 (14.2) | 186 (14.0) | 34 (15.4) | 0.648a |
| None, no. (%) | 1040 (67.0) | 894 (67.1) | 146 (66.1) | 0.817a |
| Mastectomye | ||||
| Nipple-sparing, no. (%) | 170 (10.9) | 149 (11.2) | 21 (9.5) | 0.531a |
| Simple, no. (%) | 1377 (88.7) | 1178 (88.4) | 199 (90.0) | 0.560a |
| Other, no. (%) | 6 (0.4) | 5 (0.4) | 1 (0.5) | 1 |
| Reconstruction techniquee | ||||
| Tissue expander (TE), no. (%) | 831 (53.5) | 699 (52.5) | 132 (59.7) | 0.054a |
| Direct-to-implant (DTI), no. (%) | 71 (4.6) | 62 (4.7) | 9 (4.1) | 0.833a |
| Transverse rectus abdominis (TRAM) flap, no. (%) | 121 (7.8) | 100 (7.5) | 21 (9.5) | 0.374a |
| Deep inferior epigastric perforator (DIEP) flap, no. (%) | 291 (18.7) | 251 (18.8) | 40 (18.1) | 0.865a |
| Latissimus dorsi (LD) flap, no. (%) | 49 (3.2) | 46 (3.5) | 3 (1.4) | 0.149a |
| Gluteal artery perforator (GAP) flap, no. (%) | 8 (0.5) | 7 (0.5) | 1 (0.5) | 1a |
| Superficial inferior epigastric artery (SIEA) flap, no. (%) | 48 (3.1) | 48 (3.1) | 0 (0.0) | 0.008a |
| Crossover flap, no. (%) | 60 (3.9) | 52 (3.9) | 8 (3.6) | 0.988a |
| Mixed flaps, no. (%) | 46 (3.0) | 39 (2.9) | 7 (3.2) | 1a |
| Mixed implant and autologous, no. (%) | 28 (1.8) | 28 (2.1) | 0 (0.0) | 0.057a |
| Chemotherapye | 0.584 | |||
| Received, no. (%) | 442 (28.5) | 383 (28.8) | 59 (26.7) | |
| Not received, no. (%) | 1111 (71.5) | 949 (71.2) | 162 (73.3) | |
| Reconstruction lateralitye | 0.390a | |||
| Unilateral, no. (%) | 700 (45.1) | 594 (44.6) | 106 (48.0) | |
| Bilateral, no. (%) | 853 (54.9) | 738 (55.4) | 115 (52.0) | |
| Mastectomy indicatione | 0.706a | |||
| Therapeutic, no. (%) | 1398 (90.0) | 1197 (89.9) | 201 (91.0) | |
| Prophylactic, no. (%) | 155 (10.0) | 135 (10.1) | 20 (9.0) | |
| Axillary interventione | ||||
| Axillary lymph node dissection (ALND), no. (%) | 402 (25.9) | 358 (26.9) | 44 (19.9) | 0.035a |
| Sentinel lymph node biopsy (SLNB), no. (%) | 698 (44.9) | 584 (43.8) | 114 (51.6) | 0.039a |
| None, no. (%) | 453 (29.2) | 390 (29.3) | 63 (28.5) | 0.878a |
| Socioeconomic and ethnic data | ||||
| Marital status | ||||
| Single, no. (%) | 109 (7.1) | 100 (7.5) | 9 (4.1) | 0.084a |
| Living with significant other, no. (%) | 67 (4.3) | 59 (4.5) | 8 (3.6) | 0.701a |
| Married, no. (%) | 1176 (76.1) | 1004 (75.8) | 172 (77.8) | 0.564a |
| Separated, no. (%) | 27 (1.7) | 23 (1.7) | 4 (1.8) | 1a |
| Divorced, no. (%) | 125 (8.1) | 104 (7.8) | 21 (9.5) | 0.483a |
| Widowed, no. (%) | 42 (2.7) | 35 (2.6) | 7 (3.2) | 0.825a |
| Education level | ||||
| Some high school, no. (%) | 31 (2.0) | 29 (2.2) | 2 (0.9) | 0.319a |
| High school degree, no. (%) | 121 (7.8) | 112 (8.4) | 9 (4.1) | 0.036a |
| Some college/trade school, no. (%) | 255 (16.5) | 226 (17.0) | 29 (13.1) | 0.179a |
| College/trade school degree, no. (%) | 602 (38.8) | 517 (38.9) | 85 (38.5) | 0.960a |
| Some masters/doctoral, no. (%) | 61 (3.9) | 54 (4.1) | 7 (3.2) | 0.655a |
| Masters/doctoral degree, no. (%) | 480 (31.0) | 391 (29.4) | 89 (40.3) | 0.002a |
| Working status | ||||
| Unable to work, no. (%) | 37 (2.4) | 29 (2.2) | 8 (3.6) | 0.295a |
| Unemployed, no. (%) | 31 (2.0) | 28 (2.1) | 3 (1.4) | 0.627a |
| Student, no. (%) | 10 (0.7) | 9 (0.7) | 1 (0.5) | 1a |
| Volunteer, no. (%) | 8 (0.5) | 7 (0.5) | 1 (0.5) | 1a |
| Retired, no. (%) | 141 (9.2) | 130 (9.9) | 11 (5.0) | 0.028a |
| Homemaker, no. (%) | 179 (11.6) | 152 (11.5) | 27 (12.3) | 0.842a |
| Part time employed, no. (%) | 216 (14.1) | 175 (13.3) | 41 (18.6) | 0.044a |
| Full time employed, no. (%) | 863 (56.1) | 746 (56.6) | 117 (53.2) | 0.376a |
| Other, no. (%) | 52 (3.4) | 41 (3.1) | 11 (5.0) | 0.218a |
| Household income per year | ||||
| <25,000$, no. (%) | 81 (5.4) | 74 (5.8) | 7 (3.2) | 0.171a |
| 25,000$ to 49,999$, no. (%) | 163 (10.9) | 149 (11.6) | 14 (6.5) | 0.032a |
| 50,000$ to 74,999$, no. (%) | 269 (17.9) | 232 (18.1) | 37 (17.1) | 0.787a |
| 75,000$ to 99,999$, no. (%) | 233 (15.5) | 207 (16.1) | 26 (12.0) | 0.144a |
| >100,000$, no. (%) | 754 (50.3) | 621 (48.4) | 133 (61.3) | <0.001a |
| Ethnical background | ||||
| Caucasian, no. (%) | 1398 (90.9) | 1199 (90.8) | 199 (91.7) | 0.750a |
| African American, no. (%) | 69 (4.5) | 61 (4.6) | 8 (3.7) | 0.662a |
| Asian, no. (%) | 63 (4.1) | 54 (4.1) | 9 (4.1) | 1a |
| American Indian, no. (%) | 8 (0.5) | 7 (0.5) | 1 (0.5) | 1a |
| Outcome – patient-reported satisfaction with breasts at 2-year follow-up compared to baseline | ||||
| Improvedd, no. (%) | 702 (45.2) | 602 (45.2) | 100 (45.2) | 1a |
| Decreasedd, no. (%) | 422 (27.2) | 357 (26.8) | 65 (29.4) | 0.468a |
| Stable, no. (%) | 429 (27.6) | 373 (28.0) | 56 (25.3) | 0.460a |
ALND = axillary lymph node dissection; SLNB = sentinel lymph node biopsy.
P values < 0.05 highlighted in bold.
a
P values refer to Chi-square tests for binary feature evaluation (feature true vs. feature not true).
b
P values refer to t-tests to evaluate mean differences of continuous data.
c
P values refer to differences in the development and validation set.
d
Increase or decrease equal or larger to minimal clinically important difference.
e
Variable used in the predictive models.