Table 2.
Propensity Score Analysis: Comparison of Survival of Resected N2 Patients Treated with and without Postoperative Radiation Therapy
| Model | Hazard Ratio (95% CI1) | |
|---|---|---|
| Without Adjustment for Chemotherapy Use | Adjusting for Chemotherapy Use | |
| Primary Analysis: Entire Cohort | ||
| Adjusting for Propensity Scores | 1.11 (0.97–1.27) | 1.13 (0.99–1.30) |
| Stratified by Propensity Score Quintiles | 1.12 (0.98–1.28) | 1.14 (1.00–1.30) |
| Matched Analysis | 1.10 (0.95–1.27) | 1.12 (0.97–1.29) |
| Stratified Analyses | ||
| Limited to Chemotherapy Treated Patients2 | ||
| Adjusting for Propensity Scores | 1.17 (0.88–1.56) | - |
| Stratified by Propensity Score Quintiles | 1.18 (0.89–1.58) | - |
| Matched Analysis | 1.22 (0.88–1.67) | - |
| Limited to Non-Chemotherapy Treated Patients | ||
| Adjusting for Propensity Scores | 1.13 (0.97–1.32) | - |
| Stratified by Propensity Score Quintiles | 1.14 (0.98–1.33) | - |
| Matched Analysis | 1.25 (0.96–1.32) | - |
| Limited to Patients Treated with Intermediate Complexity RT Planning | ||
| Adjusting for Propensity Scores | 1.09 (0.94–1.26) | 1.10 (0.94–1.27) |
| Stratified by Propensity Score Quintiles | 1.09 (0.94–1.27) | 1.10 (0.95–1.28) |
| Matched Analysis | 1.05 (0.91–1.21) | 1.06 (0.91–1.22) |
| Limited to Patients Treated with High Complexity RT Planning | ||
| Adjusting for Propensity Scores | 1.09 (0.87–1.38) | 1.17 (0.92–1.48) |
| Stratified by Propensity Score Quintiles | 1.13 (0.89–1.43) | 1.20 (0.95–1.54) |
| Matched Analysis | 1.09 (0.95–1.27) | 1.12 (0.97–1.29) |
| Adjusting for Time Trends | ||
| Adjusting for Propensity Scores | 1.06 (0.92–1.22) | 1.07 (0.93–1.24) |
| Stratified by Propensity Score Quintiles | 1.07 (0.93–1.22) | 1.10 (0.95–1.25) |
| Matched Analysis | 1.05 (0.91–1.21) | 1.07 (0.93–1.24) |
1
CI denotes confidence interval. The hazard ratio represents the risk of death of a patient treated with postoperative radiotherapy compared with a patient who did not received postoperative radiotherapy.
2
The analyses were restricted to patients treated with adjuvant chemotherapy.