Table 1. Descriptive Characteristics of the Patient Population.
| Characteristic | Participants, No. (%) | P value | ||
|---|---|---|---|---|
| Overall (N = 230 175) | Adjuvant radiation therapy | |||
| No (n = 218 590) | Yes (n = 11 585) | |||
| Age at diagnosis, median (interquartile range), y | 62.0 (56.0-67.0) | 62.0 (56.0-67.0) | 62.0 (57.0-67.0) | <.001 |
| Race | ||||
| White | 190 983 (83.0) | 181 549 (83.1) | 9434 (81.4) | <.001 |
| Black | 29 741 (12.9) | 28 096 (12.9) | 1645 (14.2) | |
| Other | 9451 (4.1) | 8945 (4.1) | 506 (4.4) | |
| Charlson-Deyo Comorbidity Index score | ||||
| 0 | 186 793 (81.2) | 177 416 (81.2) | 9377 (80.9) | .10 |
| 1 | 36 894 (16.0) | 35 051 (16.0) | 1843 (15.9) | |
| 2 | 5122 (2.2) | 4842 (2.2) | 280 (2.4) | |
| ≥3 | 1366 (0.6) | 1281 (0.6) | 85 (0.7) | |
| Facility type | ||||
| Community cancer program | 11 158 (4.8) | 10 355 (4.7) | 803 (6.9) | <.001 |
| Comprehensive community cancer program | 85 499 (37.1) | 80 688 (36.9) | 4811 (41.5) | |
| Academic or research program | 101 020 (43.9) | 96 618 (44.2) | 4402 (38.0) | |
| Integrated network cancer program | 32 498 (14.1) | 30 929 (14.1) | 1569 (13.5) | |
| Primary payer | ||||
| Not insured | 3395 (1.5) | 3141 (1.4) | 254 (2.2) | <.001 |
| Private insurance or managed care | 142 581 (61.9) | 135 899 (62.2) | 6682 (57.7) | |
| Medicaid | 5310 (2.3) | 4880 (2.2) | 430 (3.7) | |
| Medicare | 74 894 (32.5) | 70 952 (32.5) | 3942 (34.0) | |
| Other government | 3995 (1.7) | 3718 (1.7) | 277 (2.4) | |
| Annual median income quartiles in 2000, $US | ||||
| <30 000 | 23 582 (10.2) | 22 305 (10.2) | 1277 (11.0) | <.001 |
| 30 000-34 999 | 35 657 (15.5) | 33 783 (15.5) | 1874 (16.2) | |
| 35 000-45 999 | 61 006 (26.5) | 57 871 (26.5) | 3135 (27.1) | |
| ≥46 000 | 109 930 (47.8) | 104 631 (47.9) | 5299 (45.7) | |
| Individuals in the area with no high school degree in 2000, quartiles, % | ||||
| ≥29 | 29 573 (12.8) | 27 989 (12.8) | 1584 (13.7) | <.001 |
| 20-28.9 | 46 527 (20.2) | 44 020 (20.1) | 2507 (21.6) | |
| 14-19.9 | 54 133 (23.5) | 51 343 (23.5) | 2790 (24.1) | |
| <14 | 99 942 (43.4) | 95 238 (43.6) | 4704 (40.6) | |
| Distance from facility, median (interquartile range), milesa | 14.5 (6.4-36.9) | 14.8 (6.5-37.7) | 10.9 (4.9-24.2) | <.001 |
| Year of diagnosis, median (interquartile range) | 2012 (2011-2014) | 2012 (2011-2014) | 2013 (2011-2014) | <.001 |
| Tumor category | ||||
| T2 | 167 741 (73.0) | 165 622 (75.0) | 2119 (18.0) | <.001 |
| T3 | 61 948 (27.0) | 52 621 (24.0) | 9327 (81.0) | |
| T4 | 486 (0.2) | 347 (0.2) | 139 (1.2) | |
| Gleason score | ||||
| ≤6 | 57 588 (25.0) | 57 173 (26.0) | 415 (4.0) | <.001 |
| 7 | 145 946 (63.0) | 139 853 (64.0) | 6093 (53.0) | |
| 8-10 | 26 641 (12.0) | 21 564 (10.0) | 5077 (44.0) | |
| Lymph node invasion | ||||
| Absent | 223 051 (97.0) | 213 335 (98.0) | 9716 (84.0) | <.001 |
| Present | 7124 (3.0) | 5255 (2.0) | 1869 (16.0) | |
| Surgical margins status | ||||
| Negative | 177 759 (77.0) | 173 872 (80.0) | 3887 (34.0) | <.001 |
| Positive | 52 416 (23.0) | 44 718 (20.0) | 7698 (66.0) | |
a
To convert miles to kilometers, multiply by 1.61.