Life and Death: Apples and Oranges?

Guest Post: Carl Tollef Solberg, Ole Frithjof Norheim and Mathias Barra
Article: The Disvalue of Death in the Global Burden of Disease

The global burden of disease (GBD) study is “a systematic, scientific effort to quantify the comparative magnitude of health loss due to diseases, injuries, and risk factors by age, sex, and geographies for specific points in time.” It was initiated by the WHO in the late 1980’s, and since then, the World Bank and several universities have joined the effort. Publications reporting on the GBD regularly feature in top journals, like The Lancet and the New England Journal of Medicine. Furthermore, the GBD study – which uses the disability-adjusted life year (DALY) as its health metric – is increasingly informing policymaking. In 2007 The Institute for Health Metrics and Evaluation (IHME) marked a new era with increased activity for the GBD. On the IHME’s home-page the GBD’s DALY-driven data for charting the burden incurred by disability and mortality is described as “just like [a] gross domestic product.”

In the GBD, disease burden is measured as DALYs – a measure for burden composed of the two components years lived with disability (YLDs) and years of life lost (YLLs). The YLDs measure how much an individual is burdened by disease while still alive; the YLL on the other hand, measures how much a person is burdened by death. Thus, whereas morbidity (YLD) is something that happens to an individual, loss of life itself (YLL) occurs when that individual’s life ends or has ended. YLLs quantify something that involves no experience and does not take place among living individuals. This casts doubt on whether the YLL is an individual burden at all. If it is not, then YLDs and YLLs may be as ‘apples and oranges’.

The DALY’s greatest weakness may be that it is marketed as a mostly descriptive measure. If this dulls the perceived need for continuous questioning and updating of the underlying methodology for measuring disease burden, it might not accurately reflect what must be the ultimate aim of the GBD: in what way morbidity and mortality does matter to the peoples of the world.

We suggest a revisionary strategy for making the YLD and the YLL comparable—an appeal to counterfactual harm. This strategy, however, forces the DALY-authors to take a stance on at which developmental stage deaths begins to be bad for the one who dies.