Table 1.
Baseline patient characteristics
| Receipt of immunotherapy | No (%) | Yes (%) | Total (%) | Chi square |
|---|---|---|---|---|
| Total, n | 9,014 (75) | 2,930 (25) | 11,944 (100) | |
| Age | <.001 | |||
| <60 yr | 2,885 (32) | 1,217 (42) | 4,102 (34) | |
| ≥60 yr | 6,129 (68) | 1,713 (58) | 7,842 (66) | |
| Gender | .796 | |||
| Male | 6,102 (68) | 1,991 (68) | 8,093 (68) | |
| Female | 2,912 (32) | 939 (32) | 3,851 (32) | |
| Race | .425 | |||
| Non‐Hispanic white | 8,490 (94) | 2,767 (94) | 11,257 (94) | |
| Non‐Hispanic black | 133 (1) | 35 (1) | 168 (1) | |
| Hispanic | 238 (3) | 70 (2) | 308 (3) | |
| Other | 153 (2) | 58 (2) | 211 (2) | |
| Facility area | .001 | |||
| Metropolitan | 7,181 (80) | 2,427 (83) | 9,608 (80) | |
| Urban | 1,394 (15) | 369 (13) | 1,763 (15) | |
| Rural | 193 (2) | 50 (2) | 243 (2) | |
| Unknown | 246 (3) | 84 (3) | 330 (3) | |
| Insurance | <.001 | |||
| Commercial | 2,954 (33) | 1,314 (45) | 4,268 (36) | |
| Medicare | 4,535 (50) | 1,208 (41) | 5,743 (48) | |
| Medicaid | 711 (8) | 194 (7) | 905 (8) | |
| Uninsured | 486 (5) | 105 (4) | 591 (5) | |
| Other | 328 (4) | 109 (4) | 437 (4) | |
| Zip code education level | <.001 | |||
| ≥21% | 1,309 (15) | 300 (10) | 1,609 (13) | |
| 13%–20.9% | 2,250 (25) | 690 (24) | 2,940 (25) | |
| 7%–12.9% | 3,083 (34) | 1,032 (35) | 4,115 (34) | |
| <7% | 2,345 (26) | 903 (31) | 3,248 (27) | |
| Unknown | 27 (<1) | 5 (<1) | 32 (<1) | |
| Zip code income level | <.001 | |||
| <38,000 | 1,311 (15) | 337 (12) | 1,648 (14) | |
| 38,000–47,999 | 2,168 (24) | 612 (21) | 2,780 (23) | |
| 48,000–62,999 | 2,512 (28) | 857 (29) | 3,369 (28) | |
| ≥63,000 | 2,983 (33) | 1,119 (38) | 4,102 (34) | |
| Unknown | 40 (<1) | 5 (<1) | 45 (<1) | |
| Facility type | <.001 | |||
| Nonacademic | 5,367 (60) | 1,297 (44) | 6,664 (56) | |
| Academic | 3,215 (36) | 1,404 (48) | 4,619 (39) | |
| Unknown | 432 (5) | 229 (8) | 661 (6) | |
| Facility location | <.001 | |||
| East | 1,591 (18) | 622 (21) | 2,213 (19) | |
| South | 3,317 (37) | 880 (30) | 4,197 (35) | |
| Central | 2,042 (23) | 669 (23) | 2,711 (23) | |
| West | 1,632 (18) | 530 (18) | 2,162 (18) | |
| Unknown | 432 (5) | 229 (8) | 661 (6) | |
| Distance to treatment facility | <.001 | |||
| ≤40 miles | 7,334 (81) | 2,229 (76) | 9,563 (80) | |
| >40 miles | 1,645 (18) | 693 (24) | 2,338 (20) | |
| Unknown or missing | 35 (<1) | 8 (<1) | 43 (<1) | |
| Charlson Deyo score | <.001 | |||
| 0 | 6,662 (74) | 2,410 (82) | 9,072 (76) | |
| 1 | 1,608 (18) | 398 (14) | 2,006 (17) | |
| 2 | 484 (5) | 91 (3) | 575 (5) | |
| 3 | 260 (3) | 31 (1) | 291 (2) | |
| Surgery to metastatic site | .03 | |||
| No | 6,542 (73) | 2,068 (71) | 8,610 (72) | |
| Yes | 2,404 (27) | 829 (28) | 3,233 (27) | |
| Unknown | 68 (1) | 33 (1) | 101 (1) | |
| Brain metastasis | <.001 | |||
| None | 4,544 (50) | 1,480 (51) | 6,024 (50) | |
| Present | 2,425 (27) | 632 (22) | 3,057 (26) | |
| Unknown | 2,045 (23) | 818 (28) | 2,863 (24) | |
| Liver metastasis | <.001 | |||
| None | 5,441 (60) | 1,605 (55) | 7,046 (59) | |
| Present | 1,474 (16) | 505 (17) | 1,979 (17) | |
| Unknown | 2,099 (23) | 820 (28) | 2,919 (24) | |
| Lung metastasis | <.001 | |||
| None | 4,036 (45) | 1,111 (38) | 5,147 (43) | |
| Present | 2,893 (32) | 999 (34) | 3,892 (33) | |
| Unknown | 2,085 (23) | 820 (28) | 2,905 (24) | |
| Bone metastasis | <.001 | |||
| None | 5,646 (63) | 1,697 (58) | 7,343 (61) | |
| Present | 1,287 (14) | 416 (14) | 1,703 (14) | |
| Unknown | 2,081 (23) | 817 (28) | 2,898 (24) | |
| Receipt of chemotherapy | <.001 | |||
| No | 6,094 (68) | 2,549 (87) | 8,643 (72) | |
| Yes | 2,620 (29) | 336 (11) | 2,956 (25) | |
| Unknown | 300 (3) | 45 (2) | 345 (3) | |
| Receipt of radiotherapy | <.001 | |||
| No | 5,695 (63) | 1,736 (59) | 7,431 (62) | |
| Yes | 3,166 (35) | 1,184 (40) | 4,350 (36) | |
| Unknown | 153 (2) | 10 (<1) | 163 (1) | |
| Year of diagnosis | <.001 | |||
| 2011 | 1,859 (21) | 341 (12) | 2,200 (18) | |
| 2012 | 1,811 (20) | 356 (12) | 2,167 (18) | |
| 2013 | 1,881 (21) | 559 (19) | 2,440 (20) | |
| 2014 | 1,801 (20) | 707 (24) | 2,508 (21) | |
| 2015 | 1,662 (18) | 967 (33) | 2,629 (22) | |
| Radiation modality | <.001 | |||
| None | 5,695 (63) | 1,736 (59) | 7,431 (62) | |
| External beam radiation therapy | 2,405 (27) | 772 (26) | 3,177 (27) | |
| Stereotactic | 719 (8) | 390 (13) | 1,109 (9) | |
| Other | 42 (<1) | 22 (1) | 64 (1) | |
| Unknown | 153 (2) | 10 (<1) | 163 (1) | |
| Radiation treatment volume | <.001 | |||
| None | 5,695 (63) | 1,736 (59) | 7,431 (62) | |
| Central nervous system | 2,032 (23) | 751 (26) | 2,783 (23) | |
| Mediastinum | 118 (1) | 49 (2) | 167 (1) | |
| Liver and pancreas | 9 (<1) | 7 (<1) | 16 (<1) | |
| Bone | 368 (4) | 140 (5) | 508 (4) | |
| Skin and soft tissue | 129 (1) | 45 (2) | 174 (1) | |
| Other sites | 480 (5) | 175 (6) | 655 (5) | |
| Unknown | 183 (2) | 27 (1) | 210 (2) |
