Table 2b. Risk equations of models 3 and 4.
| Model 3 | Model 4 | |||
|---|---|---|---|---|
| incorporating pack-years and other risk factors | incorporating time since quitting in past smoking status and other risk factors | |||
| Estimate (SE) | Hazard Ratio (95% CI) | Estimate (SE) | Hazard Ratio (95% CI) | |
| Smoking variables | ||||
| Smoking status (Never smoker) | ||||
| Past smoker | 0.3167**** (0.1306) | 1.373 (1.063, 1.773) | ||
| Pack-years | ||||
| <20 | 0.3320 (0.2734) | 1.394 (0.816, 2.382) | ||
| 20–39 | 0.9049*(0.2271) | 2.472 (1.584, 3.857) | ||
| 40+ | 0.9617*(0.1789) | 2.616 (1.842, 3.714) | ||
| Time since quitting | ||||
| ≤5 years | 0.7744* (0.1823) | 2.169 (1.518,3.101) | ||
| >5 years | 0.0163 (0.1310) | 1.016 (0.786, 1.314) | ||
| Current smoker | 0.7003* (0.1373) | 2.014 (1.539,2.637) | ||
| Total | 3751 | 3751 | ||
| Event | 383 | 383 | ||
| Censored | 3368 | 3368 | ||
| % censored | 89.79 | 89.79 | ||
| x2 | P | x2 | P | |
|---|---|---|---|---|
| Test | ||||
| Likelihood ratio | 455.5912 | <0.0001 | 456.578 | <0.0001 |
| Hosmer lemeshow | 9.21449 | 0.4177 | 19.0085 | 0.0251 |
| Modified HL | 8.56713 | 0.4782 | 17.9658 | 0.0355 |
| C-statistic | ||||
| Estimate (SE) | 0.8047 (0.0110) | 0.8082 (0.0109) | ||
| 95% CI | (0.7832, 0.8263) | (0.7869, 0.8296) |
The coefficients for the smoking variables have been adjusted for the effects of age, sex, SBP, DBP, total cholesterol/HDL ratio, triglycerides, diabetes and alcohol. The reference category for a categorical variable is in the parentheses.
*,**,*** and ****
indicate P<0.0001, 0.001, 0.01 and 0.05, respectively. The statistical tests presented at the bottom of the table are for the full model versus the null model.