Cost-effectiveness plane

The cost-effectiveness plane is a two-dimensional graph used in healthcare evaluation to visually compare the differences in costs and health outcomes between treatment alternatives. Health outcomes (effects) are typically plotted on the x-axis and costs on the y-axis. ‘Current practice’ is frequently positioned at the origin, making the plotted values represent incremental health outcomes and incremental costs relative to current practice. Multiple treatment alternatives can be displayed on the plane, and the line connecting the most cost-effective options forms the cost-effectiveness frontier. The plane is divided into four quadrants: the north-east quadrant commonly shows new interventions that offer greater health gains but at a higher cost. The other quadrants represent scenarios where a new intervention yields poorer health outcomes (north-west or south-west) or lower costs (south-west or south-east). Additionally, cost-effectiveness planes are valuable for illustrating the uncertainty surrounding cost-effectiveness results, often depicted as a scatter of points representing the outcomes of a probabilistic sensitivity analysis.