Resource scarcity necessitates priority setting in health. Sound priority setting relies on reliable health measurement to identify which interventions should be made first. Deaths are a vital component of health measurements. There are approximately 55 million deaths in the world each year. How should these deaths be evaluated? Historically, epidemiology has been chiefly concerned with mortality in a population determined by descriptive measures such as crude or age-specific death rates (2). The initial descriptive mortality measures are simple, transparent, and inherently universal. Moreover, descriptive mortality measures do not reflect that individuals’ deaths are postponed rather than prevented, and they cannot state whether some deaths are worse than others. In the mid-20th century, more nuanced measures such as potential years of life lost (PYLLs) and years of life lost (YLLs) were developed (3). These latter measures are evaluative because they indicate that some deaths are worse than others. These more refined evaluative mortality measures rely on value assumptions such as ideas about a natural life span and are thereby deemed controversial. No mortality measure serves equally well for all purposes, and all mortality measures have shortcomings.
The ability to aggregate morbidity and mortality is necessary for monitoring and priority setting, and summary measures respond to this need. Quality-adjusted life years (QALYs) and disability-adjusted life years (DALYs) are the most used summary measures. Both the QALY and the DALY integrate (dis)quality of life and mortality into a single measure (4). Health economists developed QALYs based on expected utility theory, and the QALY measure matured in the late 1970s and early 1980s. Scholars determine the value of different health states by asking a representative sample of people about their own health or the health of others. In the QALY model, full health is worth 1 by convention. Values typically range from 1 to 0 but can also include negative values for health states worse than death (5,6). The numbers of the quality of a state are referred to as utility weights. Methods such as time trade-off (TTO), person trade-off (PTO), and standard gamble (SG) are the benchmarks used to establish these utility weights. QALYs can be used in cost-utility analyses to estimate the cost per QALY per intervention. For instance, the National Institute for Health Care Excellence (NICE) in the United Kingdom has implemented the QALY model in this manner (7). QALYs are also used in Australia and many European countries, such as Sweden and the Netherlands.
Disability-adjusted life years (DALYs) were developed in the early 1990s as an integral part of the Global Burden of Disease (GBD) study. GBD scholars constructed the DALY model for two reasons: first, to quantify the burden of disease, and second, to set priorities in health (3). On the DALY scale, 1 represents full disability (equivalent to death), whereas 0 represents no disability (4). One can calculate DALYs as the sum of years of life lost (YLL) relative to some ideal longevity due to mortality in the population and the years lived with disability (YLD) for people living with bad health conditions (3,8,9). Considerable work has gone into the morbidity component of QALYs and DALYs, including the development of sophisticated methods to establish disability weights for different diseases and injuries to compare these different conditions for monitoring and priority-setting purposes (4–6,10–12). Systematically asking representative samples of the general population which of two bad health conditions they would prefer is also a way to ascribe some legitimacy to the measures in question. Moreover, the value assumptions behind both the QALY and DALY models, especially their morbidity components, have been debated (e.g., (11–20)]). In contrast, there has been much less concern about value assumptions in the mortality component.
In parallel, a specific discourse has evolved within analytic philosophy since the 1970s regarding the badness of death. The main concern with this philosophical debate is to provide an adequate answer to whether death is bad for the individual who dies (22). Death here refers to the incidence of death rather than the process of dying. While any death can be bad for others, such as family, friends, and society, the question here is whether death can be bad for the individual who dies. Epicureanism promotes the view that death cannot be bad for the individual who dies. We cannot experience anything while being dead; nothing can be bad for the nonexistent; and our prenatal nonexistence is not bad for us; thus, death (posthumous nonexistence) should not be bad either (23). A majority of philosophers involved in the debate hold the opposite view, antiepicureanism: that death is, in fact, bad for the one who dies. The leading anti-epicurean view is deprivationism, which is the view that death is bad for the individual who dies because of the loss of the life that a person counterfactually could have had had they not died (22,24–26). Sophisticated accounts have been developed to answer the question of when the worst time to die is (24). Furthermore, deliberations have been held in population ethics over relevant symmetries and asymmetries between the philosophy of the harm of death and the challenges of harm and benefit for future individuals (27,28).
References
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