Figure 1

Point estimates and confidence intervals for the statistics of variation applied to the six medical procedures under the null hypothesis (homogeneity across Healthcare Areas, continuous line) and the alternative hypothesis (observed rates, dotted line). Procedures are sorted from high to low rate and grouped by low and high variability, see left axis. CI_Homogeneity: estimates and confidence intervals when the null hypothesis of homogeneity holds (continuous line); CI_{Obs.variability}; estimates and non-parametric confidence intervals for the statistics when the observed variability is considered (dotted line); EQ: extremal quotient; CV: Coefficient of variation; CVw: weighted coefficient of variation; SCV: Systematic Component of Variance; EB: Empirical Bayes. Statistic with the subindex 5–95 have been estimated excluding the areas with rates under percentile 5 and over percentile 95 for each procedure.