Components of a good economic evaluation

Drummond et al (2005) have developed a checklist of 10 questions which can be used to assess the strengths and weaknesses of individual economic evaluations. In addition, the checklist can be used at the design stage of an economic evaluation to provide guidance on how to conduct an economic evaluation.

Drummond MF, Sculpher MJ, Torrance GW et al., Methods for the economic evaluation of health care programmes. 3rd ed. 2005, Oxford: Oxford University Press.
http://www.oup.com/uk/catalogue/?ci=9780198529453

Ten questions to ask of published studies (Drummond et al, 2005)

1. Was a well-defined question posed in answerable form?

1.1 Did the study examine both costs and effects of the service(s) or programme(s)?
1.2 Did the study involve a comparison of alternatives?
1.3 Was a viewpoint for the analysis stated and was the study placed in any particular decision-making context?

2. Was a comprehensive description of the competing alternatives given? (i.e. can you tell who? did what? to whom? where? and how often?)

2.1 Were any important alternatives omitted?
2.2 Was (Should) a do-nothing alternative (be) considered?


3. Was the effectiveness of the programmes or services established?

3.1 Was this done through a randomized, controlled clinical trial? If so, did the trial protocol reflect what would happen in regular practice?
3.2 Was effectiveness established through an overview of clinical studies?
3.3 Were observational data or assumptions used to established effectiveness? If so, what are the potential biases in results?

4. Were all the important and relevant costs and consequences for each alternative identified?

4.1 Was the range wide enough for the research question at hand?
4.2 Did it cover all relevant viewpoints? (Possible viewpoints include the community or social viewpoint, and those of patients and third-party payers. Other viewpoints may also be relevant depending upon the particular analysis.)
4.3 Were capital costs, as well as operating costs, included?

5. Were costs and consequences measured accurately in appropriate physical units? (e.g. hours of nursing time, number of physician visits, lost work-days, gained life-years)

5.1 Were any of the identified items omitted from measurement? If so, does this mean that they carried no weight in the subsequent analysis? 5.2 Were there any special circumstances (e.g. joint use of resources) that made measurement difficult? Were these circumstances handled appropriately?

6. Were costs and consequences valued credibly?

6.1 Were the sources of all values clearly identified? (Possible sources include market values, patient or client preferences and views, policy-makers' views and health professionals' judgements.)
6.2 Were market values employed for changes involving resources gained or depleted?
6.3 Where market values were absent (e.g. volunteer labour), or market values did not reflect actual values (such as clinic space donated at a reduced rate), were adjustments made to approximate market values?
6.4 Was the valuation of consequences appropriate for the question posed? (i.e. Has the appropriate type or types of analysis - cost-effectiveness, cost-benefit, cost-utility - been selected?)

7. Were costs and consequences adjusted for differential timing?

7.1 Were costs and consequences which occur in the future 'discounted' to their present values?
7.2 Was any justification given for the discount rate used?

8. Was an incremental analysis of costs and consequences of alternatives performed?

8.1 Were the additional (incremental) costs generated by one alternative over another compared to the additional effects, benefits or utilities generated?

The incremental approach to the analysis of costs and consequences of say, services X compared to service Y, can be illustrated graphically (see Figure 1). If the ICER(incremental cost-effectiveness ratio ) falls in quadrant 2, then Y is more cost-effective than X and it dominates X. If the ICER falls in quadrant 4, then Y is less cost-effective than X and is dominated by X. If, however, the ICER falls in quadrant 1 or 3, cost-effectiveness depends on the maximum cost-effectiveness ratio one is willing to accept. The slope of the line (in quadrant 1) joining a point which is determined by the incremental costs and incremental effects of a service and the origin (representing existing care) is the ICER.



9. Was allowance made for uncertainty in the estimates of costs and consequences?

9.1 If data on costs or consequences were stochastic(involving chance and probability), were appropriate statistical analyses performed?
9.2 If a sensitivity analysis was employed, was justification provided for the ranges of values (for key study parameters)?
9.3 Were study results sensitive to changes in the values (within the assumed range for sensitivity analysis, or within the confidence interval around the ratio of costs to consequences)?

10. Did the presentation and discussion of study results include all issues of concern to users?

10.1 Were the conclusions of the analysis based on some overall index or ratio of costs to consequences (e.g. cost-effectiveness ratio)? If so, was the index interpreted intelligently or in a mechanistic fashion?
10.2 Were the results compared with those of others who have investigated the same question? If so, were allowances made for potential differences in study methodology?
10.3 Did the study discuss the generalizability of the results to other settings and patient/client groups?
10.4 Did the study allude to, or take account of, other important factors in the choice or decision under consideration (e.g. distribution of costs and consequences, or relevant ethical issues)?
10.5 Did the study discuss issues of implementation, such as the feasibility of adopting the 'preferred' programme given existing financial or other constraints, and whether any freed resources could be redeployed to other worthwhile programmes?