Figure 1.

Cost-effectiveness plane. The horizontal axis represents the difference in benefits between the two therapies (e.g., difference in quality-adjusted life expectancy) and the vertical axis represents the difference in the cost. Quadrant II of the plane represents a situation where a new treatment “dominates” or is always acceptable than the comparator treatment; it reflects a situation where the new therapy is less costly and more effective. The opposite occurs in Quadrant IV, where the existing therapy dominates the new treatment. Quadrant I is where a new therapy is both more effective and most costly. If the incremental benefits are attained for acceptable incremental costs (this relationship is represented by the slope of the dotted line), then the new treatment is acceptable. [Reproduced from EP Europace 2011; 13(Suppl_2):ii3–ii8 with permission].