WHO’s estimates of the excess mortality associated with the COVID-19 pandemic are also approximations in a rapidly evolving pandemic with regard to transmissibility and severity.
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值得注意的是，世卫组织依靠各种模型来编制广泛的全球卫生统计数据。
It is worth noting that WHO relies on models to compile a wide range of global health statistics.
This is necessary as not all countries have high quality information systems, or those that do cannot always share their data in a timely manner.
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因此，世卫组织会与各国合作，加强它们的数据和卫生信息系统，同时，充分利用现有数据，生成高质量证据。
Therefore, WHO works with countries to strengthen their data and health information systems, while at the same time makes the best use of the data currently available to generate high quality evidence.
Specifically with regard to the excess mortality estimates, the model uses relationships that have been quantified using data from the countries with high quality systems for data reporting.
We extrapolate these relationships to settings that are in many ways systematically different across multiple dimensions such as health systems capacity, underlying disease burden and age-structure.