Two-way sensitivity analysis is characterized by:

• A. Varies two values at same time resulting in thresholds
• B. Varies one value
• C. Ignores probabilities
• D. Uses only utilities

Answer: (D)

Two-way sensitivity analysis explores how the recommended decision changes when two uncertain inputs are varied together. By changing two parameters at once—such as a probability and a cost, or a probability and a utility—you can see where the preferred option shifts and identify the thresholds or decision boundaries in the parameter space. This joint variation reveals interactions between inputs that single-parameter analyses miss. It does not ignore probabilities; probabilities are often among the inputs varied to observe their impact on outcomes. It is also not limited to utilities, since other inputs like costs or probabilities can be varied as well. Therefore, the idea that two-way sensitivity analysis uses only utilities is not accurate.