Table 3.
Improvement in CVD risk prediction due to including age at quitting among past smokers in Model 3
| Likelihood ratio | Value | Degrees of freedom | p-value | |
|---|---|---|---|---|
| Vs model 3 | 25.8845 | 2 | <0.0001 | |
| Difference between two correlated C | Estimate (SE) | 95% CI | Chi-square | p-value |
| Vs model 3 | 0.0079(0.0036) | 0.0008,0.0150 | 4.7266 | 0.0297 |
| Estimate | 95% CI | Z | p-value | |
| NRI | ||||
| Vs model 3 | 0.0294 | -0.0111,0.0701 | 1.4192 | 0.1558 |
| IDI | ||||
| Vs model 3 | 0.0029 | 0.0001, 0.0057 | 2.0362 | 0.0417 |
Note: Model 3 incorporated smoking status that included categories for never smokers (reference group), ≤5 and >5 years for time since quitting, and <20, 20-39 and 40+ for pack-years, systolic and diastolic blood pressure, total cholesterol/HDL ratio, triglycerides, age, sex and diabetes status.