Table 2.
Prediction model coefficients
| Predictor variable | Shrunk coefficient* |
|---|---|
| Warfarin indication | |
| AFib/Aflutter | Ref |
| DVT/PE | −0.47 |
| Other | −0.33 |
| Insurance status | |
| Private insurance | Ref |
| VA/Medicare | −0.14 |
| Medicaid/None | −0.42 |
| Number MD visits in previous year | |
| <4 | −0.29 |
| 4–12 | Ref |
| >12 | −0.23 |
| Current smoker | −0.17 |
| History of heart failure | −0.21 |
*
To improve expected model calibration, coefficients were shrunk using a linear shrinkage factor, equal to 0.82, which was estimated from 1,000 bootstrap replications. Negative coefficients indicate a higher probability of prolonged dose titration.