## Table 2 |
|||||

Regression coefficients and odds ratios with 95% confidence intervals as derived from
the original model and the internally validated model |
|||||

Original model |
Model after internal validation |
||||

Variable |
Regression coefficient |
Odds ratio (95% CI) |
p-value |
Regression coefficient* |
Odds ratio (95% CI) |

Intercept | -0.32 | - | - | -0.23 | - |

Elevated sIL-2R levels | 1.98 | 7.27 (1.86 – 28.40) | 0.004 | 1.85 | 6.33 (1.73-28.17) |

Total HRCT score | 0.24 | 1.27 (1.06 - 1.52) | 0.011 | 0.22 | 1.25 (1.04-1.50) |

To calculate the absolute risk of a positive PET result: P |

CI: confidence interval; sIL-2R: soluble interleukin-2 Receptor; HRCT: high-resolution computed tomography; PET: positron emission tomography.

^{*} Regression coefficients after adjustment for overfitting by shrinkage (shrinkage
factor = 0.93); the intercept was re-estimated.

Mostard * et al.*

Mostard * et al.* *BMC Pulmonary Medicine* 2012 **12**:57 doi:10.1186/1471-2466-12-57