- 學位論文
運用蒙地卡羅模擬法估算台灣COVID-19主流變異株的疾病負擔
Measuring disease burden of dominant variants of COVID-19 in Taiwan with the implication of Monte Carlo simulation
摘要
本研究目的為利用失能調整人年(Disability-Adjusted Life Years, DALYs)估算2020年至2022年台灣不同COVID-19變異株流行下的疾病負擔。通過全球共享流感數據倡議組織(Global Initiative on Sharing All Influenza Data, GISAID)蒐集變異株流行比例，結合衛生福利部疾病管制署公開之確診與死亡人數資料、不同變異株疾病嚴重程度、失能權重與失能期間等相關參數，分析台灣隨時間推移不同變異株流行下，各性別及年齡層疾病負擔變化。最後使用蒙地卡羅模擬法對無症狀比例、失能期間和失能權重三參數進行模擬，了解參數不確定性對整體疾病負擔的影響及人年損失的變動範圍。 研究結果顯示台灣2020年、2021年和2022年COVID-19主要流行病毒株類型分別為原始病毒株(Wild-type)、Alpha變異株和Omicron變異株。疫情流行三年期間COVID-19總共造成每十萬人23,075 DALYs，其中生命損失人年(Years life lost, YLLs)為每十萬人16,373 YLLs (佔整體71%)高於失能損失人年(Years lived with disability, YLDs)的每十萬人6,703 YLDs (佔整體29%)，其中總DALYs男性貢獻55%高於女性的45%，且兩性皆在70+歲年齡層DALYs最高(佔整體50%)。在不確定性參數影響下三年YLDs變動範圍為6,937 (95% CI：5,070-8,943)人年，整體DALYs為23,309 (95% CI：21,443-25,316)人年。靈敏度分析亦顯示各年最靈敏參數為危重症狀態(Critical)的失能期間(Disability duration)長短。 總體而言，台灣COVID-19疾病負擔以死亡個案為主要貢獻，其中男性DALYs高於女性且隨著年齡增長疾病負擔也隨之增加。靈敏度分析顯示危重症狀態失能期間對整體DALYs估算影響最高，這意味著可以針對危重症之失能期間提出相對應潛在的策略來減少DALYs。本研究為台灣COVID-19疾病負擔估算，將疫情期間不同變異株的流行情況以及疾病嚴重程度納入考量，期待提供政府施行防疫政策時有更多元的參考依據。
並列摘要
The purpose of this study was to use disability-adjusted life years (DALYs) to estimate the disease burden under the prevalence of different COVID-19 variants in Taiwan from 2020 to 2022. The prevalence rate of variants was collected through the Global Initiative on Sharing All Influenza Data (GISAID), combined with the data on the number of confirmed cases and deaths published by the Centers for Disease Control and Prevention of the Ministry of Health and Welfare. The disease severity of different variants, disability weight, and disability duration were used to analyze the changes in the disease burden of different sexes and age groups in Taiwan. Finally, the Monte Carlo simulation was implicated to simulate the uncertainty of three parameters of asymptomatic proportion, disability duration, and disability weight to understand the impact of parameter uncertainty on the overall disease burden and the variation range of person-year loss. The results of the study show that the main epidemic virus types of COVID-19 in Taiwan in 2020, 2021, and 2022 are the Wild-type virus, Alpha variant, and Omicron variant, respectively. During the three years of the epidemic, COVID-19 caused a total of 23,075 DALYs per 100,000 population, of which years life lost (YLLs) was 16,373 YLLs per 100,000 population (accounting for 71%) which was higher than years lived with disability (YLDs) (6,703 YLDs per 100,000 population, accounting for 29%). Males contribute 55% of the total DALYs higher than females’ 45%, and both sexes have the highest DALYs in the 70+ age group (accounting for 50% of the total). Under the influence of uncertain parameters, the variation range of YLDs in three years was 6,937 (95% CI: 5,070-8,943) YLDs per 100,000 population, and the variation range of DALYs was 23,309 (95% CI: 21,443-25,316) DALYs per 100,000 population. Sensitivity analysis also showed that the most sensitive parameter for each year was the length of the disability duration of the critical illness state. Overall, the disease burden of COVID-19 in Taiwan is mainly caused by deaths. The DALYs of males are higher than those of females and the disease burden increases with age. Sensitivity analysis showed that the disability duration in critical illness has the greatest impact on the estimation of DALYs, which means that corresponding potential strategies can be proposed to reduce DALYs during the disability duration in critical illness. This study estimates the disease burden of COVID-19 in Taiwan, taking into account the prevalence of different variants and the severity of the disease during the epidemic, and expects to provide more diverse references for the government to implement epidemic prevention policies.