Table 1. Patient Characteristics and Logistic Regression of Variables Associated With Receipt of Sipuleucel-T.
| Characteristic | Treatment Group, No. (%) of Patients (n = 7272)a | Unadjusted Analysis, Odds Ratio (95% CI)b | Nagelkerke R2 | P Value | Multivariate Analysis, Odds Ratio (95% CI)c | |
|---|---|---|---|---|---|---|
| Sipuleucel-T (n = 730) | No Sipuleucel-T (n = 6542) | |||||
| Age, y | ||||||
| <55 | 22 (3.0) | 199 (3.0) | 1 [Reference] | 0.003 | .02 | 1 [Reference] |
| 55-64 | 120 (16.4) | 930 (14.2) | 1.17 (0.72-1.89) | 1.05 (0.63-1.73) | ||
| 65-74 | 287 (39.3) | 2321 (35.5) | 1.12 (0.71-1.77) | 1.01 (0.62-1.65) | ||
| ≥75 | 301 (41.2) | 3092 (47.3) | 0.88 (0.56-1.39) | 0.71 (0.43-1.18) | ||
| Race/ethnicity | ||||||
| White | 529 (72.5) | 4235 (64.7) | 1 [Reference] | 0.007 | <.001 | 1 [Reference] |
| Asian | 11 (1.5) | 131 (2.0) | 0.67 (0.36-1.25) | 0.71 (0.37-1.39) | ||
| Black | 87 (11.9) | 888 (13.6) | 0.78 (0.62-0.96) | 0.81 (0.61-1.09) | ||
| Hispanic | 30 (4.1) | 503 (7.7) | 0.47 (0.33-0.70) | 0.57 (0.38-0.86) | ||
| Unknown | 73 (10.0) | 785 (12.0) | 0.74 (0.57-0.96) | 0.85 (0.53-1.38) | ||
| Educational attainment | ||||||
| No college | 187 (25.6) | 1982 (30.3) | 1 [Reference] | 0.003 | .003 | 1 [Reference] |
| Some college | 488 (66.8) | 3948 (60.3) | 1.31 (1.10-1.56) | 1.11 (0.90-1.37) | ||
| Unknown | 55 (7.5) | 612 (9.4) | 0.95 (0.70-1.30) | 1.75 (0.49-6.19) | ||
| Household income, $1000 | ||||||
| <50 | 201 (27.5) | 2272 (34.7) | 1 [Reference] | 0.11 | <.001 | 1 [Reference] |
| 50-99 | 241 (33.0) | 1877 (28.7) | 1.45 (1.19-1.77) | 1.29 (1.04-1.61) | ||
| >99 | 176 (24.1) | 1183 (18.1) | 1.68 (1.36-2.08) | 1.43 (1.10-1.85) | ||
| Unknown | 112 (15.3) | 1210 (18.5) | 1.10 (0.81-1.48) | 1.03 (0.75-1.43) | ||
| Geographic regiond | ||||||
| South Atlantic | 35 (4.8) | 306 (4.7) | 1 [Reference] | <0.001 | .96 | 1 [Reference] |
| New England | 68 (9.3) | 551 (8.4) | 1.03 (0.70-1.50) | 1.03 (0.68-1.55) | ||
| Middle Atlantic | 184 (25.2) | 1651 (25.2) | 1.11 (0.82-1.49) | 0.91 (0.65-1.26) | ||
| East North Central | 106 (14.5) | 993 (15.2) | 0.96 (0.74-1.23) | 0.89 (0.67-1.18) | ||
| East South Central | 26 (3.6) | 227 (3.5) | 1.03 (0.67-1.59) | 0.91 (0.56-1.48) | ||
| West North Central | 88 (12.1) | 651 (10.0) | 1.21 (0.93-1.59) | 1.37 (1.01-1.89) | ||
| West South Central | 77 (10.5) | 654 (10.0) | 1.06 (0.80-1.40) | 1.02 (0.74-1.42) | ||
| Mountain | 98 (13.4) | 611 (9.3) | 1.44 (1.11-1.87) | 1.27 (0.93-1.75) | ||
| Pacific | 48 (6.6) | 863 (13.2) | 0.50 (0.36-0.69) | 0.66 (0.45-0.97) | ||
| Insurance type | ||||||
| HMO | 172 (23.6) | 2147 (32.8) | 1 [Reference] | 0.008 | <.001 | 1 [Reference] |
| PPO | 59 (8.1) | 536 (8.2) | 1.37 (1.01-1.87) | 1.56 (1.08-2.26) | ||
| Other | 499 (68.4) | 3859 (58.9) | 1.61 (1.35-1.93) | 1.55 (1.24-1.94) | ||
| ASO | ||||||
| No | 600 (82.2) | 5676 (86.8) | 1 [Reference] | 0.003 | .002 | 1 [Reference] |
| Yes | 130 (17.8) | 866 (13.2) | 1.42 (1.16-1.74) | 1.04 (0.82-1.32) | ||
| Metastatic | ||||||
| No | 48 (6.6) | 1145 (17.5) | 1 [Reference] | 0.02 | <.001 | 1 [Reference] |
| Yes | 682 (93.4) | 5397 (82.5) | 3.01 (2.23-4.07) | 4.74 (3.26-6.89) | ||
| Comorbid conditions | ||||||
| Diabetes | 270 (37.0) | 2180 (33.3) | 1.17 (1.01-1.38) | 0.001 | .05 | 1.16 (0.97-1.39) |
| Hypertension | 612 (83.8) | 4974 (76.0) | 1.63 (1.33-2.01) | 0.007 | <.001 | 1.53 (1.21-1.95) |
| Congestive heart failure | 260 (35.6) | 2272 (34.7) | 0.94 (0.77-1.13) | <0.001 | .50 | 0.84 (0.67-1.05) |
| Osteoporosis | 146 (20.0) | 1379 (21.1) | 2.01 (1.63-2.48) | 0.01 | <.001 | 1.84 (1.45-2.32) |
| Arrhythmia | 127 (17.4) | 620 (9.5) | 1.04 (0.89-1.22) | <0.001 | .63 | 0.95 (0.78-1.14) |
| Prescriber specialty | ||||||
| Other | 525 (71.9) | 6168 (94.3) | 1 [Reference] | 0.09 | <.001 | 1 [Reference] |
| Urologist | 205 (28.1) | 374 (5.7) | 6.44 (5.13-7.81) | 8.89 (7.10-11.11) | ||
Abbreviations: ASO, administrative services only (self-funded health plan); HMO, health maintenance organization; PPO, preferred provider organization.
a
Percentages have been rounded and may not total 100.
b
Among patients prescribed a treatment for metastatic castration-resistant prostate cancer, logistic regression of factors associated with the receipt of sipuleucel-T from 2010 to 2016 was conducted. Odds ratio estimates and Wald 95% CIs for each variable are reported. For each unadjusted model, Nagelkerke R2 and P values for a likelihood ratio test to a null model are reported.
c
For the multivariate model, Nagelkerke R2 = 0.24; P < .001.
d
See Methods section for states included in each region.