Assessing Excess Mortality of Baby Boomers from the COVID-19 Pandemic: Taiwan Naïve Omicron Infection Study

Abstract Background: Asia's elderly Baby Boomer demographic (born between 1946 and 1964) faced a huge problem during the COVID-19 pandemic due to increased all-cause mortality. We aimed to provide a unique Taiwan situation regarding the impact of Baby Boomers on excess mortalities from all causes relative to non-Baby Boomers throughout distinct times of SARS-CoV-2 mutations during the COVID-19 pandemic. Methods: The Poisson time series design with Bayesian directed acyclic graphic approach was proposed to build the background mortality prior to the COVID-19 pandemic in 2015-2019. It was then used for predicting the expected all-cause deaths compared to the reported figures during the COVID-19 pandemic period based on Taiwan residents, a naïve Omicron infection cohort. Results: Baby Boomers experienced a 2% (95% CI: 1%-3%) negative excess in 2020 (Wuhan/D614G) and a 4% (95% CI: 2%-5%) excess in 2021 (Alpha/Delta), relative to non-Baby Boomers, due to a rising mortality trend for Baby Boomers, but remained constant for non-Baby Boomers. Baby Boomer and non-Baby Boomer mortality rates soared to 9% (95% CI: 7%-10%) and 10% (95% CI: 9%-11%), respectively. Surprisingly, Baby Boomers aged 58-76 experienced the same 9% excess mortality as non-Baby Boomers aged 77 and beyond. Non-COVID-19 deaths were more prevalent among Baby Boomers than non-Baby Boomers (33% vs. 29%). Conclusion: Baby Boomers were more likely to die from COVID-19 and had more non-COVID-19 deaths than older non-Baby Boomers. For this vulnerable population, adequate access to medical care and medical capacity require more consideration.