Most used economic evaluation, particularly used in the health field. It compares the cost of two or more interventions dealing with health units. Health outcomes include heart attacks, deaths, etc. If the net cost, or cost of an intervention minus medical and productivity costs, is positive then it means a more effective intervention is also more costly. A ratio is found by dividing net cost by the change in health outcomes. If the result is negative, then the most effective intervention is less costly. The goal is to save costs while finding the intervention that will improve health outcomes.