Table 3.
Multivariable Cox proportional hazard models for each time-period and for the entire cohort3
| 1986 to 1999 (N = 397)1 |
2000 to 2008 (N = 560)1 |
1986 to 2008 (N = 957)2 |
|
|---|---|---|---|
| Characteristic | HR (95% CI) | HR (95% CI) | HR (95% CI) |
| Time-period | |||
| 2000 to 2008 | -- | -- | 1.00 (referent) |
| 1986 to 1999 | -- | -- | 1.29 (1.11 – 1.49) |
| Age, N (%) | |||
| < 50 | 1.00 (referent) | 1.00 (referent) | 1.00 (referent) |
| ≥ 50 to ≤ 59 | 1.16 (0.76 – 1.78) | 0.98 (0.70 – 1.35) | 1.04 (0.80 – 1.34) |
| ≥ 60 to ≤ 69 | 1.86 (1.23 – 2.80) | 1.06 (0.77 – 1.46) | 1.33 (1.04 – 1.69) |
| ≥ 70 | 2.32 (1.52 – 3.54) | 1.29 (0.92 – 1.81) | 1.63 (1.26 – 2.11) |
| Gender, N (%) | |||
| Female | 1.00 (referent) | 1.00 (referent) | 1.00 (referent) |
| Male | 1.30 (1.05 – 1.60) | 1.41 (1.17 – 1.70) | 1.33 (1.16 – 1.53) |
| Smoking status, N (%) | |||
| Never and Former | 1.00 (referent) | 1.00 (referent) | 1.00 (referent) |
| Current | 1.47 (1.18 – 1.84) | 1.15 (0.95 – 1.39) | 1.30 (1.12 – 1.50) |
| Diagnostic test | |||
| Histology | 1.00 (referent) | 1.00 (referent) | 1.00 (referent) |
| Cytology | 0.82 (0.59 – 1.13) | 1.53 (1.19 – 1.98) | 1.15 (0.94 – 1.40) |
| Missing/unknown | -- | 2.76 (0.38 – 19.98) | 2.35 (0.33 – 16.85) |
| Summary of first course treatment | |||
| Radiation and chemotherapy only | 1.00 (referent) | 1.00 (referent) | 1.00 (referent) |
| Chemotherapy only | 1.00 (0.78 – 1.29) | 1.33 (1.06 – 1.69) | 1.15 (0.97 – 1.37) |
| Surgery ± chemotherapy ± radiation ± other |
0.41 (0.26 – 0.64) | 0.97 (0.74 – 1.29) | 0.69 (0.55 – 0.88) |
| Chemotherapy ± radiation ± other | 1.48 (0.64 – 3.42) | 0.83 (0.53 – 1.32) | 0.83 (0.56 – 1.23) |
| None | 1.69 (0.96 – 2.94) | 3.33 (2.19 – 5.07) | 2.17 (1.57 – 3.00) |
| Missing/unknown | -- | 0.15 (0.04 – 0.63) | 0.17 (0.41 – 0.67) |
| Stage, N (%) | |||
| Limited | 1.00 (referent) | 1.00 (referent) | 1.00 (referent) |
| Extensive | 2.96 (2.28 – 3.84) | 2.83 (2.25 – 3.55) | 2.79 (2.35 – 3.30) |
| Not classifiable | 0.79 (0.41 – 1.52) | 1.31 (0.89 – 1.94) | 1.08 (0.78 – 1.49) |
Abbreviations: HR, Hazard Ratio; CI, confidence interval
Bold HRs indicate a statistically significant result
1
Patients with unknown smoking status were excluded (N = 13 for 1986 to 1999 and n = 62 for 2000 to 2008)
2
Patients with unknown smoking status were excluded (N = 75)
3
Complete follow-up data were not available on all patients. Samples sizes are based on number of patients with available vital status and follow-up information.