Global, regional, and national incidence and prevalence of systemic sclerosis.

Objectives: To estimate the global and country-specific unbiased epidemiological data of SSc.

Methods: Epidemiological studies were systematically searched in four databases. A Bayesian hierarchical linear mixed model was constructed to estimate epidemiological data.

Results: 82 studies were included and epidemiological data on SSc were missing for 83.9% of countries worldwide. The global SSc incidence and newly diagnosed population were estimated to be 8.64 per 100,000 person-years (1.78-23.57) and 0.67 million (0.14-1.84) people annually, respectively. Regarding prevalence, the global SSc prevalence and affected population were 18.87 per 100,000 persons (1.55-25.28) and 1.47 million (0.12-1.97) people, respectively. Relatively higher incidence and prevalence were observed in females, adults, and high-income level countries.

Conclusions: We provide a comprehensive synthesis of SSc epidemiology and fill data gaps in most countries. Especially in low- and middle-income countries, epidemiological studies of SSc are insufficient. Further large-scale and standardized reported epidemiological investigations of SSc are imperative.