Table 6

Simulated estimates (based on 100 simulation replications) of the size and power of the test to compare Andersen and Gill (A-G) model, frailty model, Wei-Lin-Weissfeld total time (WLW-TT) marginal model and Prentice-Williams-Petersen gap time (PWP-GT) conditional model fitted to sports injury recurrent data*

Comparison of modelsSimulated model sizeSimulated model power
Pr(P>α)=αPr(P>β)=1−β
α=0.01α=0.05α=0.101−β=0.991−β=0.951−β=0.90
A-G vs frailty0.020.040.080.990.990.92
A-G vs WLW-TT0.030.080.130.970.930.88
A-G vs PWP-GT0.030.050.110.990.960.93
Frailty vs WLW-TT0.020.050.100.960.900.86
Frailty vs PWP-GT0.010.040.090.980.930.89
WLW-TT vs PWP-GT0.010.040.180.980.900.80
  • *The re-sampling procedure was based on the Cox model in the bootstrap test and hence the extended models were not fitted for first event only when compared with the Cox regression model.