joshua devine, major, usaf, bsc

Promoting high quality, cost effective drug therapy throughout the Military Health System

Identification and Use of Published Health Economic Evaluations to Support Formulary

Decisions at the MTF

Joshua Devine, Major, USAF, BSC

2DoD Pharmacoeconomic Centerwww.pec.ha.osd.mil

Objective

• Outline an effective approach for the systematic searching and use of published health economic evaluations


Outline

• Explain the definition and purpose of economic evaluation studies

• Highlight the characteristics of a health economic evaluation

• Examine how economic evaluation studies are indexed in MEDLINE, a major bibliographic database

• Discuss simple methods for determining if the results from economic evaluations are useful in your setting


Purpose of Economic Evaluation Studies

• To ensure that the benefits from a health care program implemented are greater than the opportunity cost of such a program

• Addressing questions of

– technical efficiency or

– allocative efficiency


Economic Evaluation Studies

A FULL economic evaluation compares BOTH the

• costs AND consequences of

• two or more interventions

Requires

– identification

– measurement

– valuation

of both costs and benefits


Economic Evaluation Methodologies

• cost-minimisation analysis (CMA)

• cost-effectiveness analysis (CEA)

• cost-utility analysis (CUA)

• cost-benefit analysis (CBA)


Economic Evaluation Methodologies

Evaluative Technique Benefits Unit of Measurement

cost-effectiveness analysis

quantity of Life

OR

quality of Life

life years gained

OR

natural units

cost-utility analysisquantity +

quality of life

health years

e.g., QALYs, HYE

cost-benefit analysisquantity +

quality of life

money

e.g., willingness to pay


Partial Economic Evaluation Studies

• cost comparison/cost analysis study

• cost of illness study

• cost outcome description

• cost description


Quality of Health Economic Evaluations

• Poor study design

– weak data sources

– failure to define clearly the economic evaluation method used

– use of an inappropriate method if economic evaluation to address the research question

– omission of sensitivity analysis to test robustness of modelling


Quality of Health Economic Evaluations

• Inadequate reporting

– lack of transparency by authors

– journal editorial policy surrounding economic submissions

• Publication bias

– publication bias in the clinical literature

– motivation for conducting an economic evaluation


• Research by Zarnke and colleagues

• Bibliographic databases searched between 1991-1995 for cost-benefit analyses

• Identified studies were classified according to standard definitions

• The comprehensiveness of identified studies were also evaluated

Mislabeling and Comprehensiveness of Economic Evaluations

Zarnke et al. 1997; Journal of Clinical Epidemiology


0

5

10

15

20

25

30

35

40

Very Fairly NotVery

Cursory


68%

32%

Percent of identified studies employing appropriate

methodology

Not Appropriate

Comprehensiveness of analysis

Appropriate



• Studies labeled as CBAs in the health care literature often offer only partial program evaluation

• Health care decision-makers should apply the results of these studies cautiously

• You must carefully review the methods and assumptions used in this type of analysis




• Systematic review of cost-effectiveness studies published in 2006

• Bibliographic databases searched between 1976-2001 for cost-effectiveness analyses

• Identified 494 english language studies

• Examined the distribution of incremental cost effectiveness ratios in dollars

Bias in Published Economic Evaluations

Bell et al. 2006; BMJ


• Most published analyses report favorable incremental cost effectiveness ratios

• Studies funded by industry were more likely to report ratios below the three thresholds

• Studies of higher methodological quality were less likely to report ratios below $20,000/QALY




Bottom Line

• Use caution when interpreting economic evaluations in the literature

• Critical appraisal is a must


Searching Bibliographic Databases for Economic Evaluations

• Indexing policy

– availability of controlled vocabulary

– specificity of indexing terms

• Indexing accuracy

– clarity of description

– accurate labelling

– consistency


MEDLINE

• MeSH is the U.S. National Library of Medicine's controlled vocabulary used for indexing articles for MEDLINE/PubMed

• Using this terminology should greatly enhance your efficiency

• Can also use – related links – a command to identify similar articles


Link to MeSH Database of

Search Terms

Brief Tutorial Links on How to

Use MeSH Terms for Searches


Example

• How would you search for relevant articles on nose bleed using MeSH terminology?


MeSH Terms for Economic Evaluations

• Economics

– Costs and Cost Analysis

• Cost Allocation

• Cost-Benefit Analysis ***Target MeSH Term***

• Cost Control (+)

• Cost of Illness

• Cost Sharing (+)

• Health Care Costs (+)

• Health Expenditures (+)


Example

• How would you identify published economic evaluations for the treatment of glaucoma using MeSH terminology?


Other Sources for Economic Evaluations

Databases

• CEA Registry Tufts/NEMC (formerly Harvard CUA Database)

• Multiple European Databases (NHS EED, HEED, EURONHEED)

Journals

• Traditional medical journals (JAMA or NEJM)

• Focus on health economics (HSR or MDM)


Using Economic Evaluations for Formulary Decisions

Are the results from an economic evaluation

useful to me in my setting?

1) Is the methodology employed in the study appropriate?

2) If the results are valid, would they apply to my setting?


Guidelines for Economic Evaluations

Conduct– Pharmaceutical Reimbursement (WellpointRx)

– Methodology (NICE, PHS Panel)

Reporting– BMJ Guidelines (Drummond et al. 1996)

Appraisal– BMJ Guidelines (Drummond et al. 1996)

– Methods for the Economic Evaluation of Health Care Programmes (Drummond et al. 2005)


Check-List Example for Appraisal of Economic Evaluations

• Was a well-defined question posed in answerable form?

– Did the study examine both costs and effects of the drug under study?

– Did the study involve a comparison of alternatives?

– Was a viewpoint for the analysis stated and was the study placed in any particular decision-making context?

Drummond et al. 2005



• Was the effectiveness of the various treatments established?

– Did the study use data from randomized, controlled clinical trials?

– Was the information collected and summarized through a systematic overview?

– Were observational data or assumptions used to establish effectiveness?




• Were all relevant costs and consequences valued accurately and credibly?

– Was the range wide enough for the research question at hand?

– Were the sources of all values clearly identified?





• Was an incremental analysis of costs and consequences of alternatives performed?

– Were the additional costs generated by one alternative over another compared to the additional effects, benefits, or utilities generated?


Check-List Appraisals of Economic Evaluations

• Unrealistic to expect every study to satisfy all of the points in a check-list

• However, it can help identify and assess the strengths and weaknesses


Application of Results from Economic Evaluations

• Once deemed valid, the next step is to determine if the study results apply to you

• No clear answers to this question

• However, several factors are worth considering when evaluating results from economic evaluations


Factors Likely to Affect Cost-Effectiveness in the MHS

• Basic demography and epidemiology of disease in the population studied

• Availability of health care resources and variations in clinical practice

• Incentives to health care professionals and institutions

• Relative prices or costs

• Population values


Use of Economic Evaluations

• Momentum for use of economic evaluations continues to build

• Useful as an aid for making comparisons between interventions

• Could provide a framework for evaluating proposals for formulary additions

• In general, can be used as a systematic way of thinking or structuring problems


Conclusion

• Identification of economic evaluations is easily accomplished through MEDLINE

• The existing literature has shown gaps in quality but is improving

• Appraisal and transferability of these studies are key issues for consideration

• Economic evaluations should play a role in the formulary decision-making process


References

• Health Economics Information Resources: A Self-Study Course – available through the National Information Center on Health Services Research and Health Care Technology (NICHSR)

• Drummond et al. (2005) Methods for the economic evaluation of health care programmes (3rd ed.)

• Gold et al. (1996) Cost-effectiveness in health and medicine

joshua devine, major, usaf, bsc

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