Is economic evaluation in touch with society's health values?
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《英国医生杂志》
1 Department of Social Medicine, University of Bristol, Bristol BS8 2PR jo.coast@bristol.ac.uk
Health funding is increasingly based on the results of economic evaluation. But current methods fail to consider all society's health objectives and are too complex for policy makers to use
Introduction
Economic evaluation stems from Paretian welfare economics. It incorporates the principles that individuals are the best judges of their own wellbeing and that, if one person can be made better off without another being made worse off, there is global improvement in welfare. This value judgment is uncontroversial but, in policy terms, practically useless: few policies benefit some individuals without affecting others.
Terminology used in economic evaluation
Cost benefit analysis—Costs valued in money and compared with outcomes also valued in money
Cost effectiveness analysis—Costs valued in money and compared with a single primary outcome
Cost utility analysis—A specific form of cost effectiveness analysis in which outcomes are measured in terms of QALYs gained
QALY—Quality adjusted life year. A measure that combines length of life and quality of life (valued on an index where 1 represents perfect health and 0 represents death) into a single outcome
Cost-benefit analysis translates welfare economics into something that can inform decision making. The compensation principle is used to make interpersonal comparisons. This states that global improvement will occur if individuals gaining from change could potentially compensate those who lose and still be better off. So, if my "welfare" increases more than yours from receiving a washing machine, I could potentially compensate you and still be better off; global welfare increases if I get the washing machine and you do not. An important caveat is that compensation is not actually paid: the aim is to generate global welfare improvements and distribution is irrelevant.
Cost-benefit analysis uses individuals' willingness to pay to assess the benefit of an intervention. So, for example, if group A is willing to pay more for programme X than group B requires in compensation for the loss of programme Y, there is global welfare improvement from allocating resources to X (benefiting A) rather than Y (benefiting B). Funding programme X maximises benefit to society and is thus more efficient.
There are two difficulties with cost-benefit analysis in health care. Firstly, the use of willingness to pay to measure welfare implicitly incorporates income into decision making. This may skew allocation of healthcare resources towards the wealthy. Secondly, many people are uncomfortable with valuing length and quality of life in monetary terms and thus unwilling to participate in such exercises. These difficulties have led to the development of alternative techniques of economic evaluation and, indeed, changes in underlying theory.
Non-welfare approaches
Two potential dangers arise from following the narrow philosophy with which recent advances are associated. The first is that economic evaluation becomes margin-alised and the anxiety among health economists about its lack of influence continues to grow. The second, more worrying, is that this limited approach is followed by those who do not fully understand its basis and thus decisions are taken which neither reflect society's objectives nor its health beliefs. Discussion among economists about the NICE threshold for cost per QALY gained is a disquieting example of this phenomenon.18
An alternative is to restrict all economic evaluations to the approach of cost-consequences. Different options are contrasted clearly and explicitly in tabular form for all the relevant costs (resource use) and consequences (for a recent example see Jacklin et al19). This approach allows decision makers (on behalf of society) to impute their own values to these costs and consequences, which could differ according to local context. Decision makers can see clearly what is included and what is omitted, where information is quantitative and where qualitative. Information about implications for equity, need, and other relevant objectives can be presented as well as information about the health effect on others such as informal caregivers.
To illustrate the outputs from, and uses of, the two approaches let's examine an hypothetical analysis for a comparison of hospital at home and hospital care. The outcome is based on QALYs formed from a five dimension quality of life scale. The cost of treating the patient in the hospital at home was ￡1200 more than in hospital and made little difference to the mean number of QALYs gained (0.02), where QALYs combine information about mortality and quality of life. This results in an incremental cost per QALY gained for hospital at home of ￡60 000 ($107 000, 87 000). Using the cost effectiveness acceptability curve (figure), decision makers would estimate their maximum willingness to pay for a QALY. If, for example, this was ￡30 000, the probability that hospital at home is more cost effective is slightly less than 20%, but if their willingness to pay for an additional QALY was as high as ￡80 000, the probability that hospital at home is the more cost effective option would be more than 80%.
Cost effectiveness acceptability curve for hospital at home care versus hospital care
Summary points
Cost effectiveness analysis is based on achieving an assumed societal objective of maximising health
Little evidence exists that this is the desired objective of the public or decision makers
Use of QALYs as a single outcome measure for economic evaluation means that important health consequences are excluded
Complex technical presentation makes the findings difficult to understand and use
Cost-consequences analysis would better approach the objectives of decision makers and be easier to understand
The table shows a simplified version of the cost-consequences analysis. A full table might additionally include: anxiety and depression, pain control, carer quality of life, costs to social services, accessibility to the service. Decision makers would use the information provided in the table to make decisions or, if desired, they could also use monetary valuation or discrete choice experiments to obtain utility values for the different elements. The relative efficiency of different options would depend on the implicit or explicit values attached by decision makers to the different elements of cost and outcome.
Simplified cost-consequence analysis of hospital at home care
A cost-consequences approach would more closely meet the needs of decision makers than current practice and avoid extensive use of inadequate assumptions. Such an approach may not earn researchers the same kudos for methodological research or technical capability as current methods, but it is closer to both Paretian welfare economics and a true decision making approach. It has the additional benefit of being easily understood and thus more likely to influence decision making in practice.
The Department of Social Medicine of the University of Bristol is the lead centre of the MRC Health Services Research Collaboration. I thank Richard Smith, Shah Ebrahim, Stephen Clarke, Terry Flynn, Ingolf Griebsch, Sandra Hollinghurst, and Oya Asim for helpful comments.
Contributors and sources: JC has worked as an academic health economist for almost 15 years. She has conducted economic evaluations for various interventions, mainly in the area of service delivery and organisation and conducted qualitative research among the public and local decision makers.
Competing interests: None declared.
References
Briggs AH. Handling uncertainty in economic evaluation and presenting the results. In: Drummond M, McGuire A, eds. Economic evaluation in health care. Merging theory with practice. Oxford: Oxford University Press, 2001: 172-214.
Tsuchiya A, Williams A. Welfare economics and economic evaluation. In: Drummond M, McGuire A, eds. Economic evaluation in health care. Merging theory with practice. Oxford: Oxford University Press, 2004: 22-45.
Sugden R, Williams A. The principles of practical cost-benefit analysis. Oxford: Oxford University Press, 1978.
Brouwer WBF, Koopmanschap MA. On the economics foundations of CEA. Ladies and gentlemen, take your positions! J Health Econ 2000;19: 439-59.
Culyer AJ. Commodities, characteristics of commodities, characteristics of people, utilities, and the quality of life. In: Baldwin S, ed. Quality of life. Perspectives and policies. London: Routledge, 1989: 9-27.
Sen A. Capability and well-being. In: Nussbaum MC, ed. The quality of life. Oxford: Clarendon Press, 1993.
Birch S, Donaldson C. Valuing the benefits and costs of health care programmes: where's the `extra' in extra-welfarism? Soc Sci Med 2003;56: 1121-1133.
Loomes G, McKenzie L. The use of QALYs in health care decision making. Soc Sci Med 1989;28: 299-308.
Nord E, Richardson J, Street A, Kuhse H, Singer P. Maximising health benefits vs egalitarianism: an Australian survey of health issues. Soc Sci Med 1995;41: 1429-37.
Dolan P, Cookson R. A qualitative study of the extent to which health gain matters when choosing between groups of patients. Health Policy 2000;51: 19-30.
Klevit HD, Bates AC, Castanares T, Kirk EP, Sipes-Metzler PR, Wopat R. Prioritization of health care services. A progress report by the Oregon Health Services Commission. Arch Intern Med 1991;151: 912-6.
Allen D, Lee RH, Lowson K. The use of QALYs in health service planning. Int J Health Plann Manage 1989;4: 261-73.
Eddy DM. Oregon's methods. Did cost-effectiveness analysis fail? JAMA 1991;266: 2135-41.
New B. A good-enough service. Values, trade-offs and the NHS. London: Institute for Public Policy Research, 1999.
Richards S, Coast J. Interventions to improve access to health and social care after discharge from hospital: a systematic review. J Health Serv Res Pol 2003;8: 171-9.
Drummond M, Brown R, Fendrick AM, Fullerton P, Neumann P, Taylor R. Use of pharmacoeconomics information—report of the ISPOR task force on use of pharmacoeconomic/health economic information in health-care decision making. Value Health 2003;6: 407-16.
Hoffman C, der Schulenburg JMG, EUROMET Group. The influence of economic evaluation studies on decision making. A European survey. Health Policy 2000;52: 179-92.
Cost-effectiveness thresholds. Economic and ethical issues. London: King's Fund, Office of Health Economics, 2002.
Jacklin PB, Roberts JA, Wallace P, Haines A, Harrison R, Barber JA, et al. Virtual outreach: economic evaluation of joint teleconsultations for patients referred by their general practitioner for a specialist opinion. BMJ 2003;327: 84.(Joanna Coast, senior lect)
Health funding is increasingly based on the results of economic evaluation. But current methods fail to consider all society's health objectives and are too complex for policy makers to use
Introduction
Economic evaluation stems from Paretian welfare economics. It incorporates the principles that individuals are the best judges of their own wellbeing and that, if one person can be made better off without another being made worse off, there is global improvement in welfare. This value judgment is uncontroversial but, in policy terms, practically useless: few policies benefit some individuals without affecting others.
Terminology used in economic evaluation
Cost benefit analysis—Costs valued in money and compared with outcomes also valued in money
Cost effectiveness analysis—Costs valued in money and compared with a single primary outcome
Cost utility analysis—A specific form of cost effectiveness analysis in which outcomes are measured in terms of QALYs gained
QALY—Quality adjusted life year. A measure that combines length of life and quality of life (valued on an index where 1 represents perfect health and 0 represents death) into a single outcome
Cost-benefit analysis translates welfare economics into something that can inform decision making. The compensation principle is used to make interpersonal comparisons. This states that global improvement will occur if individuals gaining from change could potentially compensate those who lose and still be better off. So, if my "welfare" increases more than yours from receiving a washing machine, I could potentially compensate you and still be better off; global welfare increases if I get the washing machine and you do not. An important caveat is that compensation is not actually paid: the aim is to generate global welfare improvements and distribution is irrelevant.
Cost-benefit analysis uses individuals' willingness to pay to assess the benefit of an intervention. So, for example, if group A is willing to pay more for programme X than group B requires in compensation for the loss of programme Y, there is global welfare improvement from allocating resources to X (benefiting A) rather than Y (benefiting B). Funding programme X maximises benefit to society and is thus more efficient.
There are two difficulties with cost-benefit analysis in health care. Firstly, the use of willingness to pay to measure welfare implicitly incorporates income into decision making. This may skew allocation of healthcare resources towards the wealthy. Secondly, many people are uncomfortable with valuing length and quality of life in monetary terms and thus unwilling to participate in such exercises. These difficulties have led to the development of alternative techniques of economic evaluation and, indeed, changes in underlying theory.
Non-welfare approaches
Two potential dangers arise from following the narrow philosophy with which recent advances are associated. The first is that economic evaluation becomes margin-alised and the anxiety among health economists about its lack of influence continues to grow. The second, more worrying, is that this limited approach is followed by those who do not fully understand its basis and thus decisions are taken which neither reflect society's objectives nor its health beliefs. Discussion among economists about the NICE threshold for cost per QALY gained is a disquieting example of this phenomenon.18
An alternative is to restrict all economic evaluations to the approach of cost-consequences. Different options are contrasted clearly and explicitly in tabular form for all the relevant costs (resource use) and consequences (for a recent example see Jacklin et al19). This approach allows decision makers (on behalf of society) to impute their own values to these costs and consequences, which could differ according to local context. Decision makers can see clearly what is included and what is omitted, where information is quantitative and where qualitative. Information about implications for equity, need, and other relevant objectives can be presented as well as information about the health effect on others such as informal caregivers.
To illustrate the outputs from, and uses of, the two approaches let's examine an hypothetical analysis for a comparison of hospital at home and hospital care. The outcome is based on QALYs formed from a five dimension quality of life scale. The cost of treating the patient in the hospital at home was ￡1200 more than in hospital and made little difference to the mean number of QALYs gained (0.02), where QALYs combine information about mortality and quality of life. This results in an incremental cost per QALY gained for hospital at home of ￡60 000 ($107 000, 87 000). Using the cost effectiveness acceptability curve (figure), decision makers would estimate their maximum willingness to pay for a QALY. If, for example, this was ￡30 000, the probability that hospital at home is more cost effective is slightly less than 20%, but if their willingness to pay for an additional QALY was as high as ￡80 000, the probability that hospital at home is the more cost effective option would be more than 80%.
Cost effectiveness acceptability curve for hospital at home care versus hospital care
Summary points
Cost effectiveness analysis is based on achieving an assumed societal objective of maximising health
Little evidence exists that this is the desired objective of the public or decision makers
Use of QALYs as a single outcome measure for economic evaluation means that important health consequences are excluded
Complex technical presentation makes the findings difficult to understand and use
Cost-consequences analysis would better approach the objectives of decision makers and be easier to understand
The table shows a simplified version of the cost-consequences analysis. A full table might additionally include: anxiety and depression, pain control, carer quality of life, costs to social services, accessibility to the service. Decision makers would use the information provided in the table to make decisions or, if desired, they could also use monetary valuation or discrete choice experiments to obtain utility values for the different elements. The relative efficiency of different options would depend on the implicit or explicit values attached by decision makers to the different elements of cost and outcome.
Simplified cost-consequence analysis of hospital at home care
A cost-consequences approach would more closely meet the needs of decision makers than current practice and avoid extensive use of inadequate assumptions. Such an approach may not earn researchers the same kudos for methodological research or technical capability as current methods, but it is closer to both Paretian welfare economics and a true decision making approach. It has the additional benefit of being easily understood and thus more likely to influence decision making in practice.
The Department of Social Medicine of the University of Bristol is the lead centre of the MRC Health Services Research Collaboration. I thank Richard Smith, Shah Ebrahim, Stephen Clarke, Terry Flynn, Ingolf Griebsch, Sandra Hollinghurst, and Oya Asim for helpful comments.
Contributors and sources: JC has worked as an academic health economist for almost 15 years. She has conducted economic evaluations for various interventions, mainly in the area of service delivery and organisation and conducted qualitative research among the public and local decision makers.
Competing interests: None declared.
References
Briggs AH. Handling uncertainty in economic evaluation and presenting the results. In: Drummond M, McGuire A, eds. Economic evaluation in health care. Merging theory with practice. Oxford: Oxford University Press, 2001: 172-214.
Tsuchiya A, Williams A. Welfare economics and economic evaluation. In: Drummond M, McGuire A, eds. Economic evaluation in health care. Merging theory with practice. Oxford: Oxford University Press, 2004: 22-45.
Sugden R, Williams A. The principles of practical cost-benefit analysis. Oxford: Oxford University Press, 1978.
Brouwer WBF, Koopmanschap MA. On the economics foundations of CEA. Ladies and gentlemen, take your positions! J Health Econ 2000;19: 439-59.
Culyer AJ. Commodities, characteristics of commodities, characteristics of people, utilities, and the quality of life. In: Baldwin S, ed. Quality of life. Perspectives and policies. London: Routledge, 1989: 9-27.
Sen A. Capability and well-being. In: Nussbaum MC, ed. The quality of life. Oxford: Clarendon Press, 1993.
Birch S, Donaldson C. Valuing the benefits and costs of health care programmes: where's the `extra' in extra-welfarism? Soc Sci Med 2003;56: 1121-1133.
Loomes G, McKenzie L. The use of QALYs in health care decision making. Soc Sci Med 1989;28: 299-308.
Nord E, Richardson J, Street A, Kuhse H, Singer P. Maximising health benefits vs egalitarianism: an Australian survey of health issues. Soc Sci Med 1995;41: 1429-37.
Dolan P, Cookson R. A qualitative study of the extent to which health gain matters when choosing between groups of patients. Health Policy 2000;51: 19-30.
Klevit HD, Bates AC, Castanares T, Kirk EP, Sipes-Metzler PR, Wopat R. Prioritization of health care services. A progress report by the Oregon Health Services Commission. Arch Intern Med 1991;151: 912-6.
Allen D, Lee RH, Lowson K. The use of QALYs in health service planning. Int J Health Plann Manage 1989;4: 261-73.
Eddy DM. Oregon's methods. Did cost-effectiveness analysis fail? JAMA 1991;266: 2135-41.
New B. A good-enough service. Values, trade-offs and the NHS. London: Institute for Public Policy Research, 1999.
Richards S, Coast J. Interventions to improve access to health and social care after discharge from hospital: a systematic review. J Health Serv Res Pol 2003;8: 171-9.
Drummond M, Brown R, Fendrick AM, Fullerton P, Neumann P, Taylor R. Use of pharmacoeconomics information—report of the ISPOR task force on use of pharmacoeconomic/health economic information in health-care decision making. Value Health 2003;6: 407-16.
Hoffman C, der Schulenburg JMG, EUROMET Group. The influence of economic evaluation studies on decision making. A European survey. Health Policy 2000;52: 179-92.
Cost-effectiveness thresholds. Economic and ethical issues. London: King's Fund, Office of Health Economics, 2002.
Jacklin PB, Roberts JA, Wallace P, Haines A, Harrison R, Barber JA, et al. Virtual outreach: economic evaluation of joint teleconsultations for patients referred by their general practitioner for a specialist opinion. BMJ 2003;327: 84.(Joanna Coast, senior lect)