Table 3.
Univariable and multivariable Cox proportional hazard models for survival in the overall cohort
| Variable | n | Events, n (%) | Median, mo | 5‐yr survival % (95% CI) | Univariable model | Multivariable model | ||
|---|---|---|---|---|---|---|---|---|
| Cox univariable hazard ratio (95% CI) | Cox univariable, FDR‐p | Cox multivariable hazard ratio, adjusted (95% CI) | Cox multivariable likelihood ratio, FDR‐p (n = 24,493) | |||||
| SES group | <.0001 | <.0001 | ||||||
| Low | 7,044 | 2,588 (37) | 90.6 | 55.8 (54.4–57.2) | 1.53 (1.43–1.63) | 1.35 (1.26–1.46) | ||
| Mid‐low | 8,877 | 3,025 (34) | 117.5 | 59.3 (58.1–60.5) | 1.36 (1.28–1.45) | 1.29 (1.20–1.38) | ||
| Mid‐high | 9,452 | 2,890 (31) | NR | 64.3 (63.1–65.4) | 1.16 (1.09–1.23) | 1.15 (1.07–1.23) | ||
| High | 5,530 | 1,490 (27) | NR | 67.9 (66.4–69.3) | ||||
| Age group, yr | <.0001 | <.0001 | ||||||
| 18–30 | 5,822 | 2,052 (35) | 103.2 | 57.2 (55.7–58.8) | 1.19 (1.14–1.25) | 1.15 (1.09–1.21) | ||
| 31–40 | 25,081 | 7,941 (32) | 155.8 | 62.6 (61.9–63.3) | ||||
| Sex | <.0001 | <.0001 | ||||||
| Female | 14,812 | 4,567 (31) | NR | 63.5 (62.6–64.4) | ||||
| Male | 16,091 | 5,426 (34) | 120.1 | 59.8 (58.8–60.7) | 1.15 (1.11–1.20) | 1.18 (1.13–1.23) | ||
| Race | <.0001 | <.0001 | ||||||
| White | 24,039 | 7,549 (31) | NR | 62.9 (62.2–63.7) | ||||
| Black | 4,437 | 1,737 (39) | 71.9 | 53.1 (51.3–54.8) | 1.38 (1.31–1.45) | 1.20 (1.13–1.27) | ||
| Other | 2,064 | 593 (29) | NR | 64.0 (61.4–66.5) | 0.97 (0.89–1.05) | 0.93 (0.85–1.02) | ||
| Ethnicity | .222 | .0044 | ||||||
| Non‐Hispanic | 23,534 | |||||||
| Hispanic | 4,642 | 0.97 (0.92–1.02) | 0.92 (0.86–0.97) | |||||
| Stage at diagnosis | <.0001 | <.0001 | ||||||
| I | 4,125 | 329 (8) | NR | 92.0 (91.0–93.0) | ||||
| II | 5,570 | 716 (13) | NR | 85.9 (84.8–87.0) | 1.68 (1.48–1.92) | 1.63 (1.43–1.87) | ||
| III | 10,435 | 2,528 (24) | NR | 72.0 (71.0–73.1) | 3.46 (3.09–3.88) | 3.54 (3.14–4.01) | ||
| IV | 8,591 | 5,832 (68) | 23.2 | 17.6 (16.6–18.6) | 18.69 (16.72–20.90) | 15.52 (13.76–17.52) | ||
| Grade | <.0001 | <.0001 | ||||||
| Well/mod/none | 24,886 | 7,291 (29) | NR | 64.9 (64.1–65.6) | ||||
| Poorly diff | 6,017 | 2,702 (45) | 52.6 | 48.5 (47.1–50.0) | 1.75 (1.67–1.82) | 1.67 (1.59–1.75) | ||
| Side of tumor | <.0001 | <.0001 | ||||||
| Left | 22,210 | 6,922 (31) | 146.3 | 63.0 (62.2–63.8) | ||||
| Right | 5,644 | 1,831 (32) | NR | 60.6 (59.1–62.1) | 1.10 (1.05–1.16) | 1.23 (1.16–1.30) | ||
| Other | 3,049 | 1,240 (41) | 71.1 | 52.8 (50.8–54.9) | 1.49 (1.40–1.58) | 1.12 (1.05–1.20) | ||
| Surgery of the primary tumor | <.0001 | <.0001 | ||||||
| No | 5,410 | 3,210 (59) | 19.9 | 21.8 (20.4–23.2) | 4.56 (4.37–4.76) | 2.42 (2.29–2.54) | ||
| Yes | 25,493 | 6,783 (27) | NR | 69.3 (68.6–70.0) | ||||
| Chemotherapy | <.0001 | <.0001 | ||||||
| Had chemo | 20,931 | 7,599 (36) | 93.2 | 56.9 (56.1–57.7) | 1.58 (1.51–1.66) | 0.83 (0.79–0.88) | ||
| No chemo | 9,880 | 2,355 (24) | NR | 72.0 (71.0–73.0) | ||||
| Comorbidity | <.0001 | <.0001 | ||||||
| None | 28,375 | 9,115 (32) | 149.7 | 61.9 (61.2–62.5) | ||||
| 1 or more | 2,528 | 878 (35) | 108.1 | 58.1 (55.8–60.4) | 1.17 (1.09–1.25) | 1.17 (1.09–1.26) | ||
| Insurance statusa | <.0001 | N/A | ||||||
| Medicaid | 4,787 | 1,897 (40) | 62.0 | 50.5 (48.7– 52.2) | 1.07 (0.995–1.15) | N/A | ||
| Medicare | 1,051 | 463 (44) | 54.3 | 47.8 (44.1– 51.4) | 1.17 (1.05–1.30) | N/A | ||
| No insurance/unknow | 3,239 | 1,268 (39) | 69.3 | 52.5 (50.4–54.5) | 1.61 (1.52–1.71) | N/A | ||
| Private | 21,024 | 6,068 (29) | 66.2 (65.4–66.9) | N/A | ||||
| Area of Living | <.0001 | .0002 | ||||||
| Metro | 25,571 | 8,118 (32) | 155.8 | 62.3 (61.6–63.0) | ||||
| Urban/rural | 4,574 | 1,645 (36) | 101.1 | 57.2 (55.5–58.9) | 1.18 (1.11–1.24) | 1.12 (1.05–1.19) | ||
a
Insurance status was considered as a mediator (not a confounder). Therefore, it was not included in the multivariable model to evaluate the effect of SES on survival.
Abbreviations: CI, confidence interval; NR, not reached; Poorly diff., poorly differentiated; mod., moderate differentiation; SES, socioeconomic status; Undiff., undifferentiated.