Table 4

Impact of the control arm probability changes on bias

Number of studies=5	Number of patients = 100		Group ratio=1		OR=0.5		Number of simulated data sets=2500				Between-study SD=0.5
	Excluding BA0E studies						Including BA0E studies
	p_c=0.001		p_c=0.005		p_c=0.01		p_c=0.001		p_c=0.005		p_c=0.01
Methods		%bias		%bias		%bias		%bias		%bias		%bias
IV random effects	0.70	−40.6	0.68	−35.1	0.64	−28.5	0.97	−93.0	0.85	−70.8	0.76	−51.3
IV fixed effects	0.70	−40.6	0.67	−34.9	0.64	−27.3	0.96	−92.3	0.84	−68.5	0.74	−48.0
M-H random effects	0.70	−40.6	0.68	−35.1	0.64	−28.5	0.97	−93.0	0.85	−70.7	0.76	−51.3
M-H fixed effects	0.70	−40.6	0.67	−34.9	0.64	−27.3	0.96	−92.3	0.84	−68.5	0.74	−48.0
Peto	0.54	−7.8	0.52	−4.6	0.51	−1.1	0.90	−90.6	0.80	−59.5	0.67	−33.2

BA0E, both-armed zero-event; IV, inverse variance; p_c, control arm probability; M-H, Mantel-Haenszel.