Incidence and prevalence of systemic sclerosis in Thailand in year 2017-2020: a database from the Ministry of Public Health

Background A better understanding of the epidemiological profile of systemic sclerosis (SSc) in Thais could improve care, human resource deployment, and public health budgeting.Objectives We aimed to determine the incidence and prevalence of SSc in Thailand between 2017 and 2020.Methods A descriptive epidemiological study was performed using the Information and Communication Technology Center, Ministry of Public Health database, comprising all types of healthcare providers during the study period. Demographic data of patients having a primary diagnosis of M34 systemic sclerosis and over 18 years of age between 2017 and 2020 were reviewed. The incidence and prevalence of SSc were calculated as well as their respective 95% confidence intervals (CIs).Results The number of SSc cases in 2017 was 15,920 from a total Thai population of 65,204,797. The prevalence of SSc in 2017 was 24.4 per 100,000 populations (95% CI 24.0-24.8). The prevalence of SSc among women was 2 times greater than among men (32.7 vs. 15.8 per 100,000). The incidence of SSc was stable from 2018 to 2019 but dropped slightly in 2020 (7.2, 7.6, and 6.8 per 100,000 person-years, respectively). Most SSc cases were in northeastern Thailand (11.6, 12.1, and 11.1 per 100,000 person-years from 2018 to 2020, respectively) and the peak was between 60 and 69 years of age (24.6, 23.8, and 20.9 per 100,000 person-years from 2018 to 2020, respectively).Conclusion SSc is a rare disease among Thais. The disease was commonly revealed in late middle-aged women with a peak at age 60-69 years, mainly from the northeast regions. The incidence remained stable during the study period, albeit during the emergence of the coronavirus pandemic a slight decline was recorded.