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(PET-positive) = (1 / (1 + exp(-(-0.23 + 1.85 * sIL-2R + 0.22 * HRCT score)))) * 100%

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

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