Guidelines for the adoption of new technologies: a prescription for uncontrolled growth in expenditures and how to avoid the problem.

The guidelines proposed by Laupacis and associates do not stem from economic theory and are a prescription for uncontrolled growth in health care expenditure. In particular, cost-effectiveness ratios provide information relevant to allocation decisions only in very special circumstances that do not usually apply in practice. When two interventions are compared a positive cost-effectiveness ratio (the common case) can tell us, at best, what additional costs will be incurred to generate the additional outcomes. From an economic perspective the information required to determine the attractiveness of a new technology is different: the source of the additional resource requirements must be identified and the opportunity cost of their redeployment estimated. Because the cost-effectiveness ratio (cost/-QALY) is sensitive to the method chosen to calculate QALYs, guidelines that do not specify (or justify) the appropriate method for calculating outcomes are unlikely to produce comparable results (or common yardsticks). In a health care system such as Canada's in which there is always pressure to introduce more effective technology, even if it is more costly, there is a risk of using such noncomparable data to justify adoption of particular technologies. The method of technology evaluation proposed by us is consistent with the stated goal of maximizing the community's health-related well-being for a given level of resources allocated to health care and ensures that new technologies are adopted only if this adoption represents an improvement in resource allocation.