Variance models of the last age interval and their impact on life expectancy at subnational scales
Variance models of the last age interval and their impact on life expectancy at subnational scales
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DOI：
10.4054/demres.2016.35.15
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发表时间：
2016-08-23
影响因子：
2.1
通讯作者：
Bourbeau, Robert
中科院分区：
文献类型：
--
作者：
Lo, Ernest;Vatnik, Dan;Bourbeau, Robert
蒋方法是最广泛接受的估计预期寿命（LE）在国家以下规模的标准;它是唯一的方法，提供了一个方程的LE方差。然而，Chiang方差公式错误地忽略了最后一个年龄间隔的贡献。这种错误是在很大程度上未知的从业者，其影响尚未得到严格的assessed. PROTETIVEWe的目的是证明潜在的实质性作用的最后年龄间隔LE方差。我们进一步的目的是提供公式和工具，用于校正方差estimation.METHODSThe三角洲方法是用来推导方差公式的方差模型的最后一个年龄间隔的范围。校正方差测试291经验，从加拿大数据（2004年）的简略生命表。最后一个年龄间隔的死亡计数可以大大有助于LE方差，导致高估的精度和假阳性的统计测试时，使用未经校正的蒋方差。过度分散放大的贡献，而人口计数的错误具有最小的影响。CONCLUSIONSURE校正方差公式的使用是必不可少的研究，使用蒋乐。最后年龄间隔的重要作用，因此，生命表封闭方法，LE方差的证明。这些研究结果扩展到其他LE衍生的指标，如health expectation.CONTRIBUTIONWe表明，最后一个年龄间隔死亡人数可以大大有助于LE方差，从而解决了在科学文献中的歧义。我们提供了迄今为止无法获得的公式来校正Chiang LE方差方程。
BACKGROUNDThe Chiang method is the most widely accepted standard for estimating life expectancy (LE) at subnational scales; it is the only method that provides an equation for the LE variance. However, the Chiang variance formula incorrectly omits the contribution of the last age interval. This error is largely unknown to practitioners, and its impact has not been rigorously assessed.OBJECTIVEWe aim to demonstrate the potentially substantial role of the last age interval on LE variance. We further aim to provide formulae and tools for corrected variance estimation.METHODSThe delta method is used to derive variance formulae for a range of variance models of the last age interval. Corrected variances are tested on 291 empirical, abridged life tables drawn from Canadian data (2004. 2008) spanning provincial, regional, and intraregional scales.RESULTSThe last age interval death count can contribute substantially to the LE variance, leading to overestimates of precision and false positives in statistical tests when using the uncorrected Chiang variance. Overdispersion amplifies the contribution while error in population counts has minimal impact.CONCLUSIONSUse of corrected variance formulae is essential for studies that use the Chiang LE. The important role of the last age interval, and hence the life table closure method, on LE variance is demonstrated. These findings extend to other LE-derived metrics such as health expectancy.CONTRIBUTIONWe demonstrate that the last age interval death count can contribute substantially to the LE variance, thus resolving an ambiguity in the scientific literature. We provide heretofore-unavailable formulae for correcting the Chiang LE variance equation.