Figure 3.

Number of contacts identified per index participant according to index characteristics. A, Lightly shaded squares (bars) show the point estimate (95% confidence interval [95% CI]) for the number of contacts identified per index participant in the incentive-based arm, whereas darkly shaded circles show corresponding values in the household-based arm. Only the subgroups whose mean difference in the mean number of contacts per index case between arms (in at least 1 category) was greater than 0.50 are shown in this figure. Another figure showing this difference according to all measured index participant characteristics is in the Supplementary Materials. B, The difference in mean number of contacts per index participant (ie, value of lightly shaded squares minus darkly shaded circles). In this figure, numbers larger than zero indicate that the mean number of contacts per index participant among participants of a given subgroup is higher in the incentive-based arm than in the household-based arm.