Table 5.

Simulation results in a domain with ICC = 5%, Pearson correlation X1 and random effect 0.0, number of patients 100, number of centers 5

	Apparent performance			Test performance
	Standard model	Marginal risk calculation	Conditional risk calculation	Standard model	Marginal risk calculation
Harrell’s C-index †	0.82 (0.742; 0.889)	0.82 (0.743; 0.888)	0.84 (0.752; 0.913)	0.77 (0.718; 0.779)	0.77 (0.719; 0.779)
C-index within clusters ‡	0.82 (0.100)	0.82 (0.096)	0.82 (0.096)	0.77 (0.032)	0.77 (0.032)
Calibration intercept*	-0.00	0.00	0.01	0.02	0.06
Calibration intercept* within clusters ‡	-0.00 (0.295)	-0.00 (0.319)	0.01 (0.000)	-0.01 (0.537)	0.03 (0.545)
Calibration slope (overall)	1.00	0.99	1.05	0.71	0.69
Calibration slope within clusters ‡	1.06 (0.100)	1.01 (0.108)	1.07 (0.000)	0.74 (0.017)	0.72 (0.018)

* With calibration slope equal to 1 (i.e. calibration in the large).

† overall performance (2.5 and 97.5 percentiles).

‡ median of overall performance from 100 simulations (median of within cluster performances).