Sensitivity analysis of model variables. This tornado diagram represents the sensitivity of different variables included in the model. Each variable is listed, along with the associated incremental cost-effectiveness ratio (ICER). The horizontal width of each bar represents the change in cost-effectiveness of Option B+ versus Option B ($/QALY gained) as each model parameter is varied over the range given in parentheses. Variables are listed in descending sensitivity; those whose ICER values change most significantly are listed first. For reference, a vertical line indicating the Ghanaian GDP per capita is included on the graph, which demonstrates that Option B+ is a cost-effective alternative, even across a wide range of sensitivity analyses. The base case ICER value is $785/QALY gained.