Figure 2From: An accurate test for homogeneity of odds ratios based on Cochran’s Q-statisticAchieved levels for homogeneous studies, N=90. Comparison of achieved levels, at the nominal level of 0.05, for the three tests Q γ (solid line), BD (dot-dash), and \(Q_{{\chi }^{2}}\) (dash) plotted against the log odds ratio θ. Here all studies have the same parameters: 90 subjects in each study with equal arms of 45 each (N=90 and q=1/2).Back to article page