Systemic sclerosis in Israel clinical characteristics, ethnic and spatial disparities: A nationwide study.

BACKGROUND

Systemic sclerosis (SSc) is an autoimmune disease characterized by immune dysregulation, vasculopathy and fibrosis. Epidemiology, Geographical and ethnic variation of SSc in Israel has not been reported.

OBJECTIVES

To estimate SSc prevalence, incidence and mortality in Israel, and to identify ethnic and geographic patterns in disease distribution.

METHODS

We conducted a nationwide epidemiologic and ecological study of SSc across Israeli localities using Clalit Health Services data. Prevalent cases and population denominators were analysed. Spatial autocorrelation was assessed using Moran's I and Local Indicators of Spatial Association (LISA). Associations between ethnicity and SSc prevalence were examined using negative binomial regression and Bayesian spatial Poisson models, adjusting for socioeconomic status (SES).

RESULTS

The study included 3567,009 individuals from 1205 localities and 2866 SSc patients. Prevalence increased from 107 per million in 2000 to 627 per million in 2023, while incidence remained stable (≈2.8-3. 9 per 100,000/year). The standardized mortality rate was 2.88. SSc prevalence showed significant spatial autocorrelation (Moran's I = 0.065, p < 0.001), with clusters in northern Israel. In non-spatial models, Druze localities had higher prevalence than Jewish localities (PRR 1.45, 95% CI 1.04-2.01), while Arab localities did not differ. After spatial adjustment, Arab localities showed lower prevalence (RR 0.78, 95% CI 0.64-0.94). Druze localities showed the highest prevalence . Higher SES was associated with increased prevalence.

CONCLUSIONS

SSc prevalence in Israel is among the highest reported worldwide and shows marked spatial clustering. Ethnic differences vary after accounting for spatial dependence, with consistently high prevalence in Druze localities.