In the last decade, explicit priority setting has become an integral part of health care systems. Indeed, there is even an International Society on Priorities in Health Care, created in 1997 (Ham 1997). Whether it is Oregon's priority ordering of symptom treatment pairs to maximize the impact of a limited Medicaid budget (Fox and Leichter 1991), England's National Institute for Clinical Excellence's assessing priorities for new therapeutic innovations in the National Health Service (Rawlins 1999), or New Zealand's setting priorities for patients' access to cardiovascular treatment (Hadorn and Holmes 1997), techniques for judging the relative worth of different health service investments abound. As these techniques are refined, the most common addition is the incorporation of public values as part of the assessment. Priority setting is increasingly seen as combining an objective assessment of costs and effects with a more subjective assessment of patient or public preferences (Lenaghan, New, and Mitchell 1996; Lomas 1997; National Institute for Clinical Excellence 2002; Stronks et al. 1997).