Table 3.
Multivariate Fine-Gray compete-risk model of cancer-specific survival before and after inverse-probability weighting.
| Characteristics | Origin cohort | IPW cohort | |||
|---|---|---|---|---|---|
| Unadjusted sHR (95% CI) | p-value | Adjusted sHR (95% CI) | p-value | ||
| Treatment | |||||
| RT | Reference | Reference | |||
| RCT | 0.75 (0.60–0.93) | 0.008 | 0.77 (0.61–0.96) | 0.018 | |
| Year of diagnosis | |||||
| 2004–2009 | Reference | Reference | |||
| 2010–2015 | 0.91 (0.74–1.12) | 0.368 | 0.88 (0.71–1.08) | 0.22 | |
| Race | |||||
| White | Reference | Reference | |||
| Black | 0.91 (0.68–1.23) | 0.558 | 0.91 (0.66–1.25) | 0.559 | |
| Other | 1.14 (0.79–1.64) | 0.487 | 1.13 (0.77–1.66) | 0.536 | |
| Age (year) | |||||
| <65 | Reference | Reference | |||
| ≥65 | 1.13 (0.92–1.39) | 0.237 | 1.15 (0.93–1.44) | 0.204 | |
| Gender | |||||
| Female | Reference | Reference | |||
| Male | 0.90 (0.73–1.10) | 0.297 | 0.86 (0.69–1.08) | 0.207 | |
| Marital status | |||||
| Married | Reference | Reference | |||
| Single | 1.21 (0.85–1.72) | 0.296 | 1.22 (0.82–1.82) | 0.333 | |
| Divorced/separated/widowed | 1.13 (0.89–1.43) | 0.327 | 1.09 (0.86–1.40) | 0.47 | |
| Unknown | 0.78 (0.42–1.44) | 0.427 | 0.71 (0.37–1.38) | 0.317 | |
| Multifocality | |||||
| Solitary | Reference | Reference | |||
| Multifocal | 0.95 (0.73–1.24) | 0.703 | 0.98 (0.72–1.32) | 0.872 | |
| Unknown | 1.22 (0.90–1.65) | 0.208 | 1.16 (0.87–1.53) | 0.311 | |
| Lymph nodes invasion | |||||
| N0 | Reference | Reference | |||
| N1NOS | 1.09 (0.78–1.52) | 0.619 | 1.06 (0.75–1.49) | 0.759 | |
| N1a | 0.85 (0.60–1.19) | 0.333 | 0.86 (0.61–1.22) | 0.408 | |
| N1b | 0.88 (0.69–1.12) | 0.292 | 0.82 (0.62–1.08) | 0.15 | |
| NX | 0.98 (0.71–1.36) | 0.919 | 0.92 (0.67–1.26) | 0.593 | |
| Distant metastasis | |||||
| M0 | Reference | Reference | |||
| M1 | 1.97 (1.60–2.44) | <0.001 | 1.93 (1.54–2.41) | <0.001 | |
| MX | 1.39 (0.89–2.19) | 0.151 | 1.31 (0.78–2.19) | 0.306 | |
| Tumor size (cm) | |||||
| <2 | Reference | Reference | |||
| 2–4 | 1.01 (0.53–1.95) | 0.967 | 1.05 (0.58–1.93) | 0.863 | |
| ≥4 | 1.18 (0.64–2.16) | 0.603 | 1.20 (0.68–2.10) | 0.526 | |
| Unknown | 1.48 (0.77–2.86) | 0.241 | 1.56 (0.84–2.88) | 0.156 | |
| Surgery | |||||
| No | Reference | Reference | |||
| Nonthyroidectomy | 0.67 (0.51–0.88) | 0.003 | 0.66 (0.48–0.90) | 0.009 | |
| Thyroidectomy | 0.57 (0.46–0.73) | <0.001 | 0.54 (0.42–0.70) | <0.001 | |
| Tumor extension | |||||
| I | Reference | Reference | |||
| II | 1.52 (0.96–2.38) | 0.072 | 1.47 (0.88–2.44) | 0.141 | |
| III | 1.34 (0.95–1.89) | 0.098 | 1.34 (0.92–1.96) | 0.126 | |
| IV | 1.66 (1.19–2.31) | 0.003 | 1.73 (1.21–2.47) | 0.003 | |
| V | 1.77 (1.08–2.90) | 0.025 | 1.78 (1.04–3.06) | 0.035 | |
| VI | 1.15 (0.73–1.81) | 0.555 | 1.12 (0.69–1.83) | 0.642 | |
sHR, subdistribution hazard ratio; IPW, inverse-probability weighting; RCT, radiotherapy plus chemotherapy; RT, radiotherapy alone; cm, centimeter.