Figure 3.

Estimated proportion of true effects more protective than hazard ratio (HR) of 0.80 (upper) and harmful rather than protective effects (lower) as a function of hypothetical unmeasured confounding severity in each study. In each diagram, the lower and upper x-axes describe confounding severity, respectively, in terms of the bias factor in each study and the risk ratio by which hypothetical unmeasured confounder(s) would need to be associated with both dialysis initiation and mortality risk. Red horizontal line represents the threshold at which <10% of effects are more protective than HR of 0.80 (upper) or at least 50% of effects indicate harm, rather than benefits (lower); black vertical line is the estimated bias factor or, alternatively, confounding strength at which this occurs. The shaded bands represent 95% bootstrapped CIs.