Fig. 6From: On the Q statistic with constant weights in meta-analysis of binary outcomesRelative error in the level of the test for heterogeneity of risk difference, vs upper tail area, for four approximations to the null distribution of \(Q_F\) and two approximations to the null distribution of \(Q_{IV}\), when \(p_{iC} = .1\). The rows correspond to the combinations of \(\Delta = 0\) and \(\Delta = 0.35\) with \(n = 20\) and \(n = 40\)Back to article page