Sluiskes Marije H, Koster Eva A S, Goeman Jelle J, Rodríguez-Girondo Mar, Putter Hein, de Wreede Liesbeth C
Medical Statistics, Biomedical Data Sciences, Leiden University Medical Center, Leiden, The Netherlands.
Mathematical Institute, Leiden University, Leiden, The Netherlands.
BMC Med Res Methodol. 2025 May 10;25(1):126. doi: 10.1186/s12874-025-02579-1.
Vulnerable subgroups of the population, such as care home residents, often face elevated mortality risks during crises like pandemics or wars. To correctly model and interpret the excess mortality of vulnerable groups during crises, a distinction must be made between the pre-existing heightened mortality of the vulnerable group, the general population's excess mortality during the crisis, and the crisis-specific excess mortality unique to the vulnerable group.
We introduce the concept of "excess excess" mortality, which captures the extra excess mortality experienced by vulnerable groups during crises, beyond what can be explained by their excess mortality due to being vulnerable and general population excess mortality. Using individual-level data from Statistics Netherlands, we model the excess excess mortality of Dutch care home residents aged 70 and older during the Covid-19 pandemic. We extend standard relative survival methods by incorporating multiple excess mortality components and use an additive hazards model to accommodate periods of negative excess hazard.
The findings confirm the severe impact of the Covid-19 pandemic on care home residents. In general, men and older age groups experienced higher excess excess mortality, both in absolute and relative terms.
Our approach offers a new perspective on how to model and interpret excess mortality in vulnerable groups during a crisis and provides a methodological foundation for investigating excess excess mortality in other contexts.
弱势群体，如养老院居民，在大流行或战争等危机期间往往面临更高的死亡风险。为了正确模拟和解释危机期间弱势群体的超额死亡率，必须区分弱势群体先前就存在的较高死亡率、危机期间普通人群的超额死亡率以及弱势群体特有的特定于危机的超额死亡率。
我们引入了“超额超额”死亡率的概念，它捕捉了弱势群体在危机期间经历的额外超额死亡率，超出了因其脆弱性导致的超额死亡率和普通人群超额死亡率所能解释的范围。利用荷兰统计局的个体层面数据，我们对新冠疫情期间荷兰70岁及以上养老院居民的超额超额死亡率进行了建模。我们通过纳入多个超额死亡率成分扩展了标准的相对生存方法，并使用加法风险模型来适应负超额风险期。
研究结果证实了新冠疫情对养老院居民的严重影响。总体而言，无论从绝对还是相对角度来看，男性和老年群体的超额超额死亡率都更高。
我们的方法为如何在危机期间对弱势群体的超额死亡率进行建模和解释提供了新视角，并为在其他背景下研究超额超额死亡率提供了方法基础。
