Table 1. Simulation comparing empirical size of the goodness-of-fit test obtained using our model-based approach and the extrapolation method with 6 risk score groups and α=0.05 for an exponential baseline hazard function.

n	Censoring %	Type 1 error: Model-based approach	Type 1 error: Extrapolation approach	Mean observed events	Mean projected events in extrapolation approach
500	10%	0.031	0.054	314	338
500	20%	0.035	0.080	301	338
500	30%	0.018	0.161	272	338
500	40%	0.028	0.276	256	338
500	50%	0.030	0.591	232	338
200	10%	0.025	0.063	124	134
200	20%	0.026	0.088	119	134
200	30%	0.026	0.213	108	134
200	40%	0.038	0.329	101	134
200	50%	0.031	0.573	92	134

^*results based on 1000 replications for each simulation