Table 6.
Risk equation incorporating time since quitting and pack-years into smoking status (Model 3)
| Variable | Parameter Estimate | Standard Error | Chi-Square | P value | Hazard Ratio | 95% CI | |
|---|---|---|---|---|---|---|---|
| Sex | 0.66172 | 0.11252 | 34.5854 | <.0001 | 1.938 | 1.555 | 2.416 |
| Sbp | 0.03508 | 0.00306 | 131.2240 | <.0001 | 1.036 | 1.030 | 1.042 |
| Dbp | -0.04076 | 0.00621 | 43.1167 | <.0001 | 0.960 | 0.948 | 0.972 |
| Total/HDL ratio | 0.22727 | 0.03592 | 40.0381 | <.0001 | 1.255 | 1.170 | 1.347 |
| Diabetes | 0.88176 | 0.15423 | 32.6873 | <.0001 | 2.415 | 1.785 | 3.268 |
| Trglycerides | -0.00170 | 0.00059 | 8.2356 | 0.0041 | 0.998 | 0.997 | 0.999 |
| Time since quitting | |||||||
| < = 5 years | 0.75854 | 0.18123 | 17.5189 | <.0001 | 2.135 | 1.497 | 3.046 |
| >5 years | 0.13762 | 0.13059 | 1.1106 | 0.2920 | 1.148 | 0.888 | 1.482 |
| Pack years | |||||||
| <20 | 0.15632 | 0.34319 | 0.2075 | 0.6487 | 1.169 | 0.597 | 2.291 |
| 20-39 | 0.50078 | 0.21593 | 5.3785 | 0.0204 | 1.650 | 1.081 | 2.519 |
| 40+ | 0.81008 | 0.16219 | 24.9470 | <.0001 | 2.248 | 1.636 | 3.089 |
| Test | Total | Event | Censored | % Censored | |||
| 3751 | 383 | 3368 | 89.79 | ||||
| Chi-Square | DF | P value | |||||
| Likelihood Ratio | 324.1494 | 11 | <0.0001 | ||||
| Hosmer Lemeshow | 11.4700 | 9 | 0.2448 | ||||
| Modified HL | 11.0293 | 9 | 0.2737 | ||||
| Estimate | SE | 95% CI | |||||
| C statistic | 0.7601 | 0.0130 | 0.7346, 0.7856 | ||||
Note: The reference categories for sex, diabetes and the smoking variable are female, no diabetes and never smoker respectively.