Principles of cost-effectiveness research.

Recent advances in the theoretical concepts behind cost-effectiveness evaluation have led to a marked improvement of the techniques used in cost-effectiveness research. Any effective program will have not only dollar costs and dollar benefits but also nondollar costs and benefits. Cost studies evaluate the relative weights of these costs and benefits to determine whether the program's value is worth the expense. Key elements to consider include direct costs of the program, costs of future workup of treatment, costs of evaluating and treating complications resulting from the program, future medical costs averted, discounting of future costs and health effects, and a sensitivity analysis. Despite the recent theoretical advances, cost-effectiveness research raises multiple controversies, including some key ethical issues.