Figure 4.

Observed relative risks compared to the relative risk of the true simulated cluster. For the Figure 2 simulations, dots represent median values and the solid lines are the 95 and 5 percentiles for each distribution. The true relative risk has a stochastic distribution as the actual number of locations in a cluster could vary a little from the specified risk when some locations were on the boundary of the defining circle or rectangle. As in Figure 1, there is a vertical line at a true relative risk of 1.7.