Economic analysis of randomized, controlled trials.

To facilitate the comparison of different treatment strategies, measures have been developed that bring together clinical, quality-of-life, and economic outcomes into summary measures such as the quality-adjusted life year, cost-effectiveness, and cost-utility ratios. A number of different types of economic evaluations have been developed, including cost-minimization, cost-effectiveness, and cost-utility analyses. Performance of economic analyses in association with randomized, controlled trials (RCT) has gained increasing enthusiasm in recent years. However, economic measures in RCTs are often outcomes of secondary interest and associated with frequent missing data and inadequate sample size. Variability in the cost measures used and the lack of agreement on clinically meaningful cost differences further limit the conclusions derived from such studies. Economic analyses should be limited to large trials with important trade-offs between efficacy and cost. The strengths and limitations of such analyses are discussed, and guidelines are offered for proper economic analyses in randomized, controlled trials.