台灣COVID-19疫情流行期間之超額死亡估計

Estimation of excess mortality during COVID-19 pandemic in Taiwan

目標：全死因超額死亡率能全面性的量化疫情的影響程度，包含直接與間接影響。本研究旨在估計COVID-19疫情流行期間，台灣及各縣市的超額死亡。方法：收集2010年至2019年各縣市歷月死亡人數資料、各年齡層人口數及總人口數資料進行準卜瓦松迴歸分析。在考慮月份效應、人口老化程度及總人口數之後，獲得加權迴歸係數建立死亡預測訓練後模型，預測2020年至2022年歷月之預期死亡數。超額死亡率定義為觀察死亡數減去預期死亡數，再除以總人口數，並以每十萬人為單位計算。結果：2020年各縣市未出現超額死亡。2021年全國歷月加總後未觀察到超額死亡，但三級警戒期間台北市及新北市有超額死亡產生。2022年5月之後受到大規模Omicron侵襲，各縣市的超額死亡均大幅提升，全國超額死亡數20,702人，間接(非COVID-19)超額死亡比例佔29.9%。間接超額死亡比例前五名分別為新竹縣、嘉義縣、雲林縣，苗栗縣及新北市，介於42%–61%之間。結論：超額死亡可反應疫情的嚴重程度；其中，間接超額死亡似乎對醫療資源較少的縣市影響較大，需要政策來均衡醫療資源分配，避免更多間接超額死亡。

Objectives: Excess mortality (EM) is a comprehensive indicator for quantifying the direct and indirect effects of the COVID-19 pandemic. This study estimated EM in Taiwan during the COVID-19 pandemic. Methods: Monthly mortality data (2010–2019) and population statistics of counties and cities in Taiwan were collected for quasi-Poisson regression analysis. After the effects of month, aging, and total population were adjusted, weighted regression coefficients were obtained to construct a predictive model for the expected number of deaths in 2020–2022. EM is obtained using the following formula: reported number of deaths−expected number of deaths. Results: In 2020, no EM was observed at either national or regional levels. In 2021, EM was observed during the Level 3 alert period in Taipei City and New Taipei City. A COVID-19 variant (Omicron) broke out in May 2022, after which EM substantially increased. In 2022, EM of 20,702 was observed, of which 29.9% was indirect EM (not related to COVID-19). The five regions with the highest proportions of indirect EM were Hsinchu County, Chiayi County, Yunlin County, Miaoli County, and New Taipei City (42%–61%). Conclusions: EM can serve as an indicator of pandemic severity. Notably, regions with limited healthcare resources reported a higher proportion of indirect EM, highlighting the pandemic’s role in impairing healthcare accessibility in these regions. Thus, policy interventions are necessary to balance the distribution of medical resources and mitigate indirect EM.