OBJECTIVES: Understanding the relationship of health metrics to health values is critical to the success of the prior in allowing us to satisfy the latter. This paper has three objectives: to demonstrate that health metrics necessarily entail normative assumptions which amount to a theory of the value of health, to explore the normative assumptions which underlies prominent health metrics (esp. QALYs and DALYs), and to raise questions about the suitability of these assumptions with an eye towards brining health metrics in line with health values.

METHODS: This paper employs philosophical analysis of the concept of health, close examination of the presumptions of prominent health metrics, and uses empirical and intuitive counter-cases to reveal shortcomings of those presumptions.

RESULTS: First, we show that health metrics, in the process of quantifying health outcomes, must commit both to a theory of health and to a theory of why and how health outcomes are morally and politically important. Second, we show that QALYs and DALYs make difficult to defend assumptions about each of these, which raises serious questions about their appropriateness. These difficulties include widely commented upon empirical shortcomings, but also more fundamental implications that these metrics make about what health is and why it matters. Third, we show that addressing these assumptions and improving the metrics will require deeper and more explicit engagement with the corresponding theoretical discourse, and that progress can be made by looking more closely at health values.

CONCLUSIONS:

Despite their considerable value in guiding policy, health metrics often depend on questionable understandings of health and its value. Considering health value more closely will allow us to improve our metrics, as well as the practices which depend on them.