Barendregt J J, Bonneux L, Van der Maas P J
Department of Public Health, Erasmus University, Rotterdam, Netherlands.
Bull World Health Organ. 1996;74(4):439-43.
In studies for the 1993 World development report: investing in health Murray et al. developed the disability-adjusted life year (DALY). This article examines one particular aspect of the DALY methodology: the weighting of life years by age. For the quantitative implementation of this notion Murray proposed a general equation to weight life years by age, which specifies that the years lived between the ages of 9 and 54 years have a weight greater than unity, and for the years outside this range less than unity. The age-weighted life years are used to calculate the "expected years of life lost" (EYLL). Comparison of age-weighted and unweighted age-specific life expectancies shows that the age range which becomes more important due to weighting is not 9-54 years, but 0-27 years. This happens because the EYLL is an age-weighting system in itself, emphasizing the young. The result of piling one age-weighting system on top of the other gives an even stronger emphasis on the young than the EYLL generates by itself. Although this is unlikely to upset the results from the Global Burden of Disease study, we do not think it is desirable. And it is certainly different from what we were led to expect.
在为《1993年世界发展报告：投资于健康》所做的研究中，默里等人提出了伤残调整生命年（DALY）。本文探讨了DALY方法的一个特定方面：按年龄对生命年进行加权。为了从定量角度落实这一概念，默里提出了一个按年龄对生命年进行加权的通用方程，该方程规定，9岁至54岁之间度过的年份权重高于1，而在此范围之外的年份权重低于1。年龄加权生命年用于计算“预期寿命损失年数”（EYLL）。对年龄加权和未加权的特定年龄预期寿命进行比较后发现，由于加权而变得更为重要的年龄范围不是9岁至54岁，而是0岁至27岁。出现这种情况是因为EYLL本身就是一个年龄加权系统，它更强调年轻人。将一个年龄加权系统叠加在另一个之上的结果是，相比于EYLL自身产生的结果，它对年轻人的强调更为强烈。尽管这不大可能扰乱全球疾病负担研究的结果，但我们认为这并不可取。而且这肯定与我们原本的预期不同。
