Impact of influenza vaccination on seasonal mortality in the US elderly population
Impact of influenza vaccination on seasonal mortality in the US elderly population
复制标题
DOI：
10.1001/archinte.165.3.265
复制
发表时间：
2005-02-14
影响因子：
--
通讯作者：
Miller, MA
中科院分区：
文献类型：
--
作者：
Simonsen, L;Reichert, TA;Miller, MA
背景：观察性研究报告称，流感疫苗接种可将老年人冬季全因死亡风险降低 50%。美国老年人（大于或等于65岁）的流感疫苗接种覆盖率从1980年之前的15%至20%增加到2001年的65%。出乎意料的是，这一年龄段的流感相关死亡率估计值在此期间也有所增加。我们试图通过调整老龄化和甲型H3N2流感病毒传播增加的超额死亡率估计来调和这些相互矛盾的发现。方法：我们使用循环回归模型来生成1968年至2001年33个季节中老年人肺炎和流感以及全因死亡中与流感相关的死亡率（超额死亡率）的季节性估计。我们对数据进行了分层 按 5 岁年龄组划分，并将 A(H3N2) 病毒主导的季节与其他季节分开。结果：对于 65 至 74 岁的人群，A(H3N2) 病毒主导季节的超额死亡率在 1968 年至 1980 年代初有所下降，但此后基本保持不变。对于 85 岁或以上的人来说，死亡率始终保持平稳。甲型H1N1流感和乙型流感季节的超额死亡率没有变化。 65 岁或以上人群的全因超额死亡率从未超过所有冬季死亡人数的 10%。结论：我们将 1968 年流感大流行后十年内 65 至 74 岁人群流感相关死亡率的下降归因于人们获得了对新出现的 A(H3N2) 病毒的免疫力。我们无法将 1980 年后疫苗接种覆盖率的提高与任何年龄组死亡率的下降联系起来。由于任何季节的所有冬季死亡中只有不到 10% 是由流感引起的，因此我们得出的结论是，观察性研究大大高估了疫苗接种的益处。
Background: observational studies report that influenza vaccination reduces winter mortality risk from any cause by 50% among the elderly. Influenza vaccination coverage among elderly persons ( greater than or equal to65 years) in the United States increased from between 15% and 20% before 1980 to 65% in 2001. Unexpectedly, estimates of influenza-related mortality in this age group also increased during this period. We tried to reconcile these conflicting findings by adjusting excess mortality estimates for aging and increased circulation of influenza A(H3N2) viruses.Methods: We used a cyclical regression model to generate seasonal estimates of national influenza-related mortality (excess mortality) among the elderly in both pneumonia and influenza and all-cause deaths for the 33 seasons from 1968 to 2001. We stratified the data by 5-year age group and separated seasons dominated by A(H3N2) viruses from other seasons.Results: For people aged 65 to 74 years, excess mortality rates in A(H3N2)-dominated seasons fell between 1968 and the early 1980s but remained approximately constant thereafter. For persons 85 years or older, the mortality rate remained flat throughout. Excess mortality in A(H1N1) and B seasons did not change. All-cause excess mortality for persons 65 years or older never exceeded 10% of all winter deaths.Conclusions: We attribute the decline in influenza-related mortality among people aged 65 to 74 years in the decade after the 1968 pandemic to the acquisition of immunity to the emerging A(H3N2) virus. We could not correlate increasing vaccination coverage after 1980 with declining mortality rates in any age group. Because fewer than 10% of all winter deaths were attributable to influenza in any season, we conclude that observational studies substantially overestimate vaccination benefit.