Can health impact be measured?

Yes, The most common form of standardisation is the Quality Adjusted Life Year or QALY. An alternative metric, more common in global health, is the Disability Adjusted Life Year or DALY.

Health impact is usually measured using some form of cost-effectiveness analysis (CEA). The origins of this idea go back several hundred years,1 but the idea first began to be thought about in health in the 1960s and 1970s. By the 1970s and 1980s, CEAs began to appear in major medical journals.2 There are several reasons for this interest in measuring health impact. Rising costs of healthcare made the trade-off between resources and health outcomes more acute.3 The ‘epidemiological transition’, which reduced the death rate amongst older people without improving life expectancy at birth substantially, also rendered raw life expectancy too blunt a tool to measure health progress.4

Cost effectiveness analysis in health entails measuring the consequences of an intervention, adjusting the consequences according to some measure of utility, and then dividing the costs of the intervention by the weighted consequences.5

There are many ways of conducting a CEA. In its most basic form CEA can be used without adjusting the consequences at all. Under this form of CEA, one simply divides the cost by the number of lives saved, or of cases diagnosed, or of some other unit used to describe the consequences.6 The problem with this approach is that it then hard to compare between interventions: is $100 for a successful hip replacement more or less effective than $100 for a cancer diagnosis? Because of this drawback, it is now more common to standardise when using CEAs.7 The most common form of standardisation is the Quality Adjusted Life Year or QALY.8 This metric assigns a year of perfect health the value 1, and death the value 0. All states of health short of perfect health can then be measured on this scale, which functions as a weighting reflecting the health-related quality of life of the outcome.9 An alternative metric, more common in global health,10 is the Disability Adjusted Life Year or DALY. This also adjusts the value of a year of life, but using the severity of particular disabling health outcome as a weighting.11

There are also alternative approaches to measuring health impact besides CEA:


Cost-consequence analyses do not allow for comparison between times and places, which is essential to evaluating health impact. CUA is a subset of CEA. CBA enjoyed early popularity and solid economic theoretical grounding, but it has now become less popular.14 This is in large part because of the technical difficulty associated with converting health outcomes into monetary terms.15

It has now become widely accepted in the academy that cost-effectiveness analysis be used to asses health interventions.16 Policy makers in the US are still sometimes resistant to CEA, which has been more successful academically than politically.17 But in many other countries, CEA is a well-established technique for assessing health impact and making policy decisions. In Europe, Canada and Australia cost-effectiveness is used in setting prices for pharmaceuticals.18 NICE is perhaps the most famous example of cost-effectiveness analysis being employed in health care.19

Bibliography

Neumann, Peter J. Using Cost-Effectiveness Analysis to Improve Health Care [Electronic Resource]: Opportunities and Barriers. Oxford Scholarship Online. New York ; Oxford: Oxford University Press, 2005. https://ezproxy-prd.bodleian.ox.ac.uk/login?url=http://dx.doi.org/10.1093/acprof:oso/9780195171860.001.0001.

Murray, Christopher J. L. Summary Measures of Population Health [Electronic Resource]: Concepts, Ethics, Measurement and Applications. Ebook Central. Geneva: World Health Organization, 2002. https://ezproxy-prd.bodleian.ox.ac.uk/login?url=http://ebookcentral.proquest.com/lib/oxford/detail.action?docID=284707.

Drummond, Michael. Methods for the Economic Evaluation of Health Care Programmes. 3rd ed. Oxford Medical Publications. Oxford: Oxford University Press, 2005.

Gold, Marthe R. Cost-Effectiveness in Health and Medicine [Electronic Resource]. Ebook Central. New York: Oxford University Press, 1996. https://ezproxy-prd.bodleian.ox.ac.uk/login?url=http://ebookcentral.proquest.com/lib/oxford/detail.action?docID=679610.


  1. Neumann, Using Cost-Effectiveness Analysis to Improve Health Care [Electronic Resource], p. 11. [return]
  2. Neumann, Using Cost-Effectiveness Analysis to Improve Health Care [Electronic Resource], p. 12. [return]
  3. Neumann, Using Cost-Effectiveness Analysis to Improve Health Care [Electronic Resource], p. 10. [return]
  4. Murray, Summary Measures of Population Health [Electronic Resource], xiii. [return]
  5. Drummond, Methods for the Economic Evaluation of Health Care Programmes, p. 2. [return]
  6. Neumann, Using Cost-Effectiveness Analysis to Improve Health Care [Electronic Resource], p. 8. [return]
  7. Neumann, Using Cost-Effectiveness Analysis to Improve Health Care [Electronic Resource], p. 8. [return]
  8. Drummond, Methods for the Economic Evaluation of Health Care Programmes, p. 3. [return]
  9. Gold, Cost-Effectiveness in Health and Medicine [Electronic Resource], p. 171. [return]
  10. Gold, Cost-Effectiveness in Health and Medicine [Electronic Resource], p. 23. [return]
  11. Gold, Cost-Effectiveness in Health and Medicine [Electronic Resource], p. 171. [return]
  12. Neumann, Using Cost-Effectiveness Analysis to Improve Health Care [Electronic Resource], p. 8. [return]
  13. Drummond, Methods for the Economic Evaluation of Health Care Programmes, p. 3. [return]
  14. Neumann, Using Cost-Effectiveness Analysis to Improve Health Care [Electronic Resource], p. 14. [return]
  15. Drummond, Methods for the Economic Evaluation of Health Care Programmes, p. 3. [return]
  16. Neumann, Using Cost-Effectiveness Analysis to Improve Health Care [Electronic Resource], p. 8. [return]
  17. Neumann, Using Cost-Effectiveness Analysis to Improve Health Care [Electronic Resource], pp. 3-6. [return]
  18. Neumann, Using Cost-Effectiveness Analysis to Improve Health Care [Electronic Resource], p. 7. [return]
  19. Gold, Cost-Effectiveness in Health and Medicine [Electronic Resource], xx. [return]