Table 2. Univariate and multivariate Cox analysis of the effect of SES on CSS and OS in ICC.
| Variable | Patient No. (%) | CSS | OS | ||||
|---|---|---|---|---|---|---|---|
| Univariate analysis, HR (95% CI) | Multivariate analysis, HR (95% CI) | Univariate analysis, HR (95% CI) | Multivariate analysis, HR (95% CI) | ||||
| Gender | |||||||
| Male | 1,763 (51.0) | Reference | Reference | Reference | Reference | ||
| Female | 1,693 (49.0) | 0.837 (0.771–0.910)** | 0.807 (0.723–0.902)** | 0.901 (0.833–0.975)* | 0.807 (0.726–0.897)** | ||
| Age at diagnosis, year | |||||||
| <45 | 168 (4.9) | Reference | Reference | Reference | Reference | ||
| 45–65 | 1,461 (42.3) | 1.349 (1.100–1.654)* | 1.397 (1.072–1.819)* | 1.330 (1.091–1.622)* | 1.401 (1.080–1.817)* | ||
| 65+ | 1,827 (52.9) | 1.801 (1.472–2.205)** | 1.845 (1.417–2.403)** | 1.827 (1.501–2.222)** | 1.919 (1.480–2.487)** | ||
| Race | |||||||
| White | 2,698 (78.1) | Reference | Reference | Reference | Reference | ||
| Black | 285 (8.2) | 1.107 (0.957–1.280) | 1.050 (0.868–1.270) | 1.116 (0.970–1.285) | 1.113 (0.928–1.336) | ||
| Other | 468 (13.5) | 0.953 (0.845–1.074) | 0.977 (0.828–1.152) | 0.968 (0.863–1.087) | 0.976 (0.833–1.146) | ||
| Marital status | |||||||
| Married | 2,041 (59.1) | Reference | Reference | Reference | Reference | ||
| Unmarried | 1,415 (40.9) | 1.230 (1.134–1.335)** | 1.229 (1.097–1.377)** | 1.225 (1.132–1.326)** | 1.205 (1.079–1.345)* | ||
| Insurance status | |||||||
| Uninsured | 611 (17.7) | Reference | Reference | Reference | Reference | ||
| Insured | 2,845 (82.3) | 0.810 (0.728–0.900)** | 0.846 (0.731–0.979)* | 0.785 (0.710–0.869)** | 0.813 (0.706–0.936)* | ||
| Education level‡ | |||||||
| < Quartile 1 (9.53%) | 2,645 (76.5) | Reference | Reference | Reference | Reference | ||
| < Quartile 2 (13.06%) | 307 (8.9) | 1.190 (1.034–1.369)* | 1.119 (0.924–1.355) | 1.191 (1.039–1.365)* | 1.135 (0.942–1.369) | ||
| < Quartile 3 (18.74%) | 450 (13.0) | 1.193 (1.057–1.347)* | 1.200 (0.981–1.467) | 1.229 (1.094–1.381)* | 1.022 (0.955–1.210) | ||
| ≥ Quartile 3 (18.74%) | 54 (1.6) | 1.324 (0.985–1.780) | 1.136 (0.779–1.656) | 1.333 (1.001–1.776)* | 1.178 (0.817–1.697) | ||
| Unemployment rate‡ | |||||||
| < Quartile 1 | 125 (3.6) | Reference | Reference | ||||
| < Quartile 2 | 743 (21.5) | 1.128 (0.892–1.426) | – | 1.129 (0.898–1.420) | – | ||
| < Quartile 3 | 1484 (42.9) | 1.129 (0.900–1.416) | – | 1.146 (0.9149–1.429) | – | ||
| ≥ Quartile 3 | 1104 (31.9) | 1.219 (0.969–1.533) | – | 1.241 (0.993–1.552) | – | ||
| Median household income‡ | |||||||
| <Quartile 1 (US $5,289) | 865 (25.0) | Reference | Reference | Reference | Reference | ||
| <Quartile 2 (US $5,995) | 892 (25.8) | 0.887 (0.793–0.992)* | 0.793 (0.672–0.936)* | 0.903 (0.810–0.989)* | 0.806 (0.709–0.915)* | ||
| <Quartile 3 (US $7,446) | 852 (24.7) | 0.835 (0.746–0.934)* | 0.853 (0.725–0.946)* | 0.840 (0.753–0.937)* | 0.813 (0.713–0.927)* | ||
| ≥Quartile 3 (US $7,446) | 847 (24.5) | 0.774 (0.690–0.868)** | 0.749 (0.630–0.891)* | 0.804 (0.720–0.869)** | 0.801 (0.696–0.921)* | ||
| Residence‡ | |||||||
| Metro area | 3,099 (89.7) | Reference | Reference | Reference | Reference | ||
| Non–metro urban area | 241 (7.0) | 1.164 (0.999–1.355) | 1.167 (0.946–1.440) | 1.135 (0.978–1.318) | 1.160 (0.943–1.427) | ||
| Non–metro rural area | 93 (2.7) | 1.350 (1.067–1.708)* | 1.229 (0.892–1.692) | 1.337 (1.063–1.680)* | 1.213 (0.884–1.664) | ||
| T category | |||||||
| T1 | 891 (25.8) | Reference | Reference | Reference | Reference | ||
| T2 | 400 (11.6) | 1.057 (0.929–1.202) | 1.042 (0.881–1.2338) | 1.030 (0.910–1.167)** | 1.273 (1.122–1.444)** | ||
| T3 | 772 (22.3) | 1.381 (1.225–1.558)** | 1.228 (1.077–.1402)* | 1.339 (1.192–1.505)** | 1.303 (1.179–1.440)** | ||
| T4 | 406 (11.7) | 1.438 (1.247–1.658)** | 1.255 (1.074–1.467)* | 1.397 (1.216–1.604)** | 1.257 (1.110–1.422)** | ||
| N category | |||||||
| N0 | 2,089 (60.4) | Reference | Reference | Reference | Reference | ||
| N1 | 820 (23.7) | 1.165 (1.056–1.285)* | 1.034 (0.917–1.167) | 1.141 (1.037–1.256)* | 1.035 (0.920–1.164) | ||
| M category | |||||||
| M0 | 1,672 (48.4) | Reference | Reference | Reference | Reference | ||
| M1 | 1,461 (42.3) | 1.903 (1.744–2.076)** | 1.478 (1.320–1.656)** | 1.841 (1.692–2.003)** | 1.437 (1.287–1.605)** | ||
| First–course surgery | |||||||
| No | 2,872 (83.1) | Reference | Reference | Reference | Reference | ||
| Yes | 577 (16.7) | 0.215 (0.186–0.250)** | 0.284 (0.240–0.337)** | 0.220 (0.190–0.254)** | 0.228 (0.244–0.339)** | ||
‡, all data are county-level; education level is the percentage of patients aged ≥25 years with at least a high school diploma. *, P<0.050; **, P value ≤0.001. CI, confidence interval. Other races (American Indian/AK Native, Asian/Pacific Islander). CSS, cause-specific survival; ICC, intrahepatic cholangiocarcinoma; OS, overall survival; TNM, tumor-node metastasis; SES, socioeconomic status