Figure 4

Results of the perturbation analysis for the hypothetical population in Table  2 (A: perturbation test when the unmeasured is associated with neither exposure nor disease; B: perturbation test when the unmeasured is not associated with exposure but is associated with disease; C: perturbation test when the unmeasured is not associated with disease but is associated with exposure; D: perturbation adjustment when the unmeasured is associated with neither exposure nor disease; E: perturbation adjustment when the unmeasured is not associated with exposure but is associated with disease; F: perturbation adjustment when the unmeasured is not associated with disease but is associated with exposure; solid lines: f _PV  = 0.05; dotted lines: f _PV  = 0.025; horizontal lines: standardized relative risks).