Increased Mortality Among Young Systemic Sclerosis Patients During the COVID-19 Pandemic: A Nationwide Data Analysis from Thailand

<b>Background:</b> Beyond the direct COVID-19 effects, the pandemic's broader impact on vulnerable groups, such as patients with systemic sclerosis (SSc), is particularly concerning, especially regarding any resulting increase in overall mortality due to healthcare access disruptions. We aimed to determine excess all-cause mortality in SSc patients before and during the pandemic. <b>Methods:</b> We examined mortality data from Thailand's Ministry of Public Health database for adults with SSc (ICD-10: M34). According to the WHO methodology, a negative binomial distribution model was used to estimate the expected number of deaths using pre-pandemic data (1 January 2015-31 December 2019). We evaluated actual versus expected deaths during the pandemic (1 January 2020 to 31 December 2022), defining excess mortality as the difference between observed and projected deaths under normal conditions. <b>Results:</b> The total number of all-cause deaths in Thailand was 2,325,384 in the pre-pandemic period and 1,634,121 during the pandemic period. The mortality rate among patients with SSc was 3693 before and 3107 during the pandemic. Of those with SSc, 1785 of the deceased were female, and the observed mortality was significantly lower than expected, with an excess death count of -368 (95% CI: -459 to -277), as well as in males with an excess death count of -123 (95% CI: -198 to -48). However, younger SSc patients (aged 18-29 years) experienced significantly higher excess mortality, with an excess death count of 11 (95% CI: 4-18). <b>Conclusions:</b> During the COVID-19 pandemic, neither sex had significantly higher SSc mortality; however, mortality in younger SSc patients increased significantly compared to pre-pandemic levels, underscoring the need for tailored therapies.