Skip to main content
. Author manuscript; available in PMC: 2023 Mar 23.
Published in final edited form as: Radiother Oncol. 2020 Apr 30;146:200–204. doi: 10.1016/j.radonc.2020.03.003

Table 4.

Bootstrap validation of model performance

Performance measure Apparent Bootstrap mean (95% CI) Validated mean (95% CI) Optimism mean (95% CI) Optimism-corrected mean (95% CI)
Overall
Nagelkerke’s R2 0.315 0.318 (0.210–0.427) 0.304 (0.274–0.334) 0.014 (−0.096–0.124) 0.301 (0.191–0.411)
Scaled Brier score 0.242 0.245 (0.161–0.329) 0.235 (0.221–0.250) 0.010 (−0.071–0.091) 0.232 (0.150–0.313)
Discrimination
AUC 0.785 0.787 (0.737–0.836) 0.785 (0.777–0.792) 0.002 (−0.047–0.052) 0.783 (0.733–0.832)
Discrimination slope 0.237 0.242 (0.164–0.321) 0.238 (0.199–0.277) 0.004 (−0.040–0.048) 0.233 (0.189–0.277)
Calibration
Hosmer-Lemeshow test χ2 = 12.01 (p = 0.21)

AUC = area under the receiver operator curve; CI = confidence interval.