The use of electronic healthcare records for colorectal cancer screening referral decisions and risk prediction model development

Table 4 Optimism calculated performance for the C statistic, c-slope, D statistic and R² for the multivariable models

Statistic	Apparent Performance	Optimism (100 bootstrap replications)	Optimism adjusted performance (apparent minus optimism)
Model for participants with positive and negative FOBT results
C statistic	0.863	0.002	0.860
c-slope	1.000	0.003	0.997
D statistic	2.519	0.028	2.491
R²	0.602	0.005	0.597
Model for negative FOBT patients only
C statistic	0.604	0.007	0.597
c-slope	1.000	0.060	0.940
D statistic	0.572	0.039	0.533
R²	0.072	0.010	0.062

ISSN: 1471-230X