National Information Center on Health Services Research and Health Care Technology (NICHSR)
Health Economics Information Resources: A Self-Study Course: Module 4
Module 4: An Introduction to the Principles of Critical Appraisal of Health Economic Evaluation Studies
Two questions need to be addressed in relation to the measurement of benefits in an economic evaluation:
3a) Is the measure of benefit appropriate?
The main difference between the different types of economic methodologies is in how the benefits are measured and valued. Here we look at cost-effectiveness analysis (CEA), cost-utility analysis (CUA), and cost-benefit analysis (CBA) in terms of their strengths and limitations.
Economic evaluation - identification and measurement of benefits
Cost-effectiveness analysis (CEA) is relatively easy to undertake and the benefits are measured as a single unidimensional outcome; however, other potentially important outcomes may be ignored. This unidimensionality may result in drawing erroneous conclusions from CEA.
Cost-utility analysis (CUA) has its own strengths and limitations. CUA measures more aspects of health and well-being than a single natural unit. QALYs and HYEs assume that the only potential benefit from health care is improvement in health-related quality of life. The different methods available to estimate QALYs may not provide identical results and CUA is more complex to undertake than CEA.
Cost-benefit analysis (CBA) is the only form of evaluation that addresses whether the benefits of an intervention exceed its costs. Willingness To Pay allows measurement of potential benefits of health care other than just health gain. It is difficult to assign monetary values to health care benefits. Lastly, CBA can be very complex, and expensive, to undertake.
3b) Is the method used to obtain clinical data valid?
The key questions to consider here are: A) do the methods used to provide measures of clinical effectiveness on which the evaluation was based provide unbiased estimates? and B) what is the underlying design of the clinical effectiveness study?
The accepted hierarchy for design of studies to assess clinical effectiveness applies; i.e., meta-analysis, individual RCTs etc.*
* Devereaux PJ, Yusuf S. The evolution of the randomized controlled trial and its role in evidence-based decision making. J Intern Med. 2003 Aug;254(2):105-13.