Section 9 Line graph of two-way sensitivity analysis

Two-way sensitivity analysis plotValue function used for convenience (administration route)

Short name	Description
Name/rubric	Two-way sensitivity analysis plot.
Created in	R
Message	To show how the changes in both the number of patients developing PML and the weight associated with PML affect the benefit-risk score. It shows the sensitivity of benefit-risk balance, for values of a variable (here % of patients with PML) for different weights of that parameter.
Intended audience	Statisticians and regulators.
Knowledge required	Need to understanding of concept of weights, as well as know the probabilities of PML events. Users also need to know that negative BR values represent poorer outcomes.
Unintentional message	Low PML weight might be interpreted as lower preference to experiencing PML..
Message not communicated	The choice of particular weight values is unclear from the graph. There is also no mention that the lines only represent benefit-risk scores against plausible proportions of patients who may experience PML with treatment
Proposed improvement	The graph could be somewhat confusing to someone with a lack of background knowledge on the problem at hand; perhaps more explanation in the way of a title or annotation is required. Explanation of weights choice is also required. More distinct colours should be used to discriminate the effects of different weights.