Chang Angela Y, Robinson Lisa A, Hammitt James K, Resch Stephen C
Department of Global Health and Population, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
Center for Health Decision Science, Harvard T.H. Chan School of Public Health, Boston, MA, USA; Center for Risk Analysis, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
J Glob Health. 2017 Jun;7(1):010401. doi: 10.7189/jogh.07.010401.
In "Global health 2035: a world converging within a generation," Commission on Investing in Health (CIH) adds the value of increased life expectancy to the value of growth in gross domestic product (GDP) when assessing national well-being. To value changes in life expectancy, the CIH relies on several strong assumptions to bridge gaps in the empirical research. It finds that the value of a life year (VLY) averages 2.3 times GDP per capita for low- and middle-income countries (LMICs) assuming the changes in life expectancy they experienced from 2000 to 2011 are permanent.
The CIH VLY estimate is based on a specific shift in population life expectancy and includes a 50 percent reduction for children ages 0 through 4. We investigate the sensitivity of this estimate to the underlying assumptions, including the effects of income, age, and life expectancy, and the sequencing of the calculations.
We find that reasonable alternative assumptions regarding the effects of income, age, and life expectancy may reduce the VLY estimates to 0.2 to 2.1 times GDP per capita for LMICs. Removing the reduction for young children increases the VLY, while reversing the sequencing of the calculations reduces the VLY.
Because the VLY is sensitive to the underlying assumptions, analysts interested in applying this approach elsewhere must tailor the estimates to the impacts of the intervention and the characteristics of the affected population. Analysts should test the sensitivity of their conclusions to reasonable alternative assumptions. More work is needed to investigate options for improving the approach.
在《2035年全球健康：一代人之内的世界融合》中，健康投资委员会（CIH）在评估国民福祉时，将预期寿命增加的价值与国内生产总值（GDP）增长的价值相加。为了评估预期寿命的变化，CIH依靠几个强有力的假设来弥合实证研究中的差距。它发现，假设低收入和中等收入国家（LMICs）在2000年至2011年期间经历的预期寿命变化是永久性的，那么生命年价值（VLY）平均为人均GDP的2.3倍。
CIH对VLY的估计基于人口预期寿命的特定变化，并且对0至4岁儿童的价值减少了50%。我们研究了这一估计对基本假设的敏感性，包括收入、年龄和预期寿命的影响以及计算顺序。
我们发现，关于收入、年龄和预期寿命影响的合理替代假设可能会使LMICs的VLY估计值降至人均GDP的0.2至2.1倍。取消对幼儿的价值减少会增加VLY，而颠倒计算顺序会降低VLY。
由于VLY对基本假设敏感，有兴趣在其他地方应用这种方法的分析人员必须根据干预措施的影响和受影响人群的特征来调整估计值。分析人员应测试其结论对合理替代假设的敏感性。需要开展更多工作来研究改进该方法的选项。
