Table 6

Impact of the between-study variance changes on bias

Number of studies=5	Control group probability=0.001		Group ratio=1		OR=0.5		Number of simulated data sets=2500				Number of patients per arm=100
	Excluding BA0E studies						Including BA0E studies
	SD=0.1		SD=0.5		SD=1		SD=0.1		SD=0.5		SD=1
Methods		%bias		%bias		%bias		%bias		%bias		%bias
IV random effects	0.68	−35.3	0.70	−40.6	0.88	−76.7	0.96	−92.5	0.97	−93.0	0.99	−97.3
IV fixed effects	0.68	−35.3	0.70	−40.6	0.88	−76.7	0.96	−91.6	0.96	−92.3	0.99	−97.0
M-H random effects	0.68	−35.3	0.70	−40.6	0.88	−76.7	0.96	−92.5	0.97	−93.0	0.99	−97.3
M-H fixed effects	0.68	−35.3	0.70	−40.6	0.88	−76.7	0.96	−91.6	0.96	−92.3	0.99	−97.0
Peto	0.50	−0.9	0.54	−7.8	0.80	−60.5	0.95	−89.9	0.90	−90.6	0.98	−96.4