Analysis of multicenter clinical trials with very low event rates

Table 4 Power, mean estimated odds ratio (OR), convergence rate (%), and coverage of 95% confidence intervals when the number of centers was 100, the ICC was 0.025, the event rate was 10%, the participant distribution across centers was skewed, and the true OR (conditional) was greater than 1

Number of participants (n) and true OR	Measurement	Unadjusted	RE	MH	GEE	GEE-small sample correction
n = 200 True OR, 3.0	Power	0.805	0.807	NA	0.809	0.791
	MCSE (power)	0.006	0.006	NA	0.006	0.006
	Mean	3.1	3.25	NA	3.1	3.1
	MCSE (mean)	0.006	0.006	NA	0.006	0.006
	Convergence	100	100	0	99.94	99.9
	Coverage	0.958	0.959	NA	0.955	0.958
	MCSE (coverage)	0.006	0.003	NA	0.003	0.003
n = 500 True OR, 2.08	Power	0.804	0.807	0.779	0.809	0.794
	MCSE (power)	0.006	0.006	0.038	0.006	0.006
	Mean	2.08	2.11	2.11	2.08	2.08
	MCSE (mean)	0.004	0.004	0.024	0.004	0.004
	Convergence	100	100	2.44	100	100
	Coverage	0.956	0.954	0.959	0.951	0.952
	MCSE (coverage)	0.003	0.003	0.018	0.003	0.003
n = 1000 True OR, 1.71	Power	0.803	0.807	0.780	0.806	0.798
	MCSE (power)	0.006	0.006	0.006	0.006	0.006
	Mean	1.7	1.71	1.71	1.7	1.7
	MCSE (mean)	0.003	0.003	0.003	0.003	0.003
	Convergence	100	100	95.94	100	100
	Coverage	0.950	0.949	0.949	0.947	0.949
	MCSE (coverage)	0.003	0.003	0.003	0.003	0.003
n = 5000 True OR, 1.29	Power	0.793	0.795	0.783	0.799	0.788
	MCSE (power)	0.006	0.006	0.006	0.006	0.006
	Mean	1.28	1.28	1.28	1.28	1.28
	MCSE (mean)	0.001	0.001	0.001	0.001	0.001
	Convergence	100	100	100	100	100
	Coverage	0.949	0.949	0.949	0.943	0.944
	MCSE (coverage)	0.003	0.003	0.003	0.003	0.003

The average actual number of centers was 87, 99, 100, and 100
GEE generalized estimating equations, MH Mantel–Haenszel, RE random-effects (i.e., random intercept), MCSE Monte Carlo standard errors

ISSN: 1745-6215