Fig. 3
Plots of posterior class a and class b misclassifications according to the decision thresholds for each of the 13 pairs of priors for severe intraventricular haemorrhage. This figure represents the posterior rates of misclassifications for each pair of priors. Prior 1 is the non-informative prior, with α1,j=α0,j=β1,j=β0,j=1; Prior 2 to 13 are distinguished by (i) the means for the difference between the two arms: E(π1,j−π0,j)=0 for prior 2, 3, 4 and 5; E(π1,j−π0,j)=median(dj,e) for prior 6, 7, 8 and 9; and E(π1,j−π0,j)=π0,j for prior 10, 11, 12 and 13; (ii) their precision: 1 for prior 2, 6 and 10; 1/3 for prior 3, 7 and 11; 1/10 for prior 4, 8 and 12; and 1/20 for prior 5, 9 and 13. For each prior, the red solid line represents the number of posterior class a misclassifications (trials that conclude that the difference between arms is Unacceptable, while it is not true) at the final analysis, according to each final threshold. The blue solid line represents the number of posterior class b misclassifications (trials that conclude that the difference between arms is Acceptable, while it is not true)