Be careful when estimating years of life lost: quick-and-dirty estimates of attributable risk are, well, quick and dirty.

Peter Morfeld writes:

Global burden of disease (GBD) studies and environmental burden of disease (EBD) studies are supported by hundreds of scientifically well-respected co-authors, are published in high level journals, are cited world wide and have a large impact on health institutions‘ reports and related political discussions.

The main metrics used to calculate the impact of exposures on the health of populations are „numbers of premature deaths“, DALYs („disability adjusted life years“) and YLLs („Years of Life Lost“). This large and influential branch of science overlooks seminal papers published by Robins and Greenland in the 1980s. These papers have shown that „etiologic deaths“ (premature deaths due to exposure) cannot be identified from epidemiological data alone which entails that YLLs and DALYs cannot be broken down by age or endpoints (diseases). DALYs due to exposure are problematic when interpreted in a counterfactual setting. Thus, most of this influential GBD and EBD mainstream work is scientifically unjustified.

We published a paper on this issue (open access):

Hammitt JK, Morfeld P, Tuomisto JT, Erren TC. Premature Deaths, Statistical Lives, and Years of Life Lost: Identification, Quantification, and Valuation of Mortality Risks. Risk Anal. 2019 Dec 10. doi: 10.1111/risa.13427.

Just for some additional background when you like to comment on the issue: Here is a letter exchange in Lancet with the leader of the largest GBD (global burden of disease) project world wide (Christopher Murray, Seattle).

This exchange is not covered in our paper. It may give an indication how the arguments and bias calculations are received.

My only comment is that I still think Qalys (or Dalys or whatever) are a good unit of measurement. The problems above are not with qualys, but with intuitively appealing but problematic statistical estimates of them. What joker put seven dog lice in my Iraqi fez box?

P.S. That above-linked discussion also involves Ty Beal, whose name rang a bell . . . here it is!