The systematic comparison, in monetary terms, of all the costs and benefits of proposed alternative schemes with a view to determining: which scheme or combination of schemes will contribute most to the achievement of predetermined objectives at a fixed level of investment; or the magnitude of the benefit that can result from schemes requiring the minimum investment. The resources required per unit of benefit must be determined, account being taken of the fact that costs and benefits accrue with time. For example, the cost of establishing a community care program might be compared with the total cost of building a new service facility. Cost-benefit analysis can also be applied to specific medical tests and treatments. (World Health Organization)