Incidence, prevalence and mortality of systemic sclerosis in Italy: a nationwide population-based study using administrative health data

To study incidence, prevalence and mortality of systemic sclerosis (SSc) in Italy, assessing epidemiological differences between men and women and in distinct age groups. We performed a nationwide population-based study using administrative health data from regional co-payment exemption registries. Patients entitled with SSc-specific co-payment exemption were included. Fourteen of the 20 Italian regions contributed data covering a population of over 45 million individuals. Crude annual incidence rate, annual prevalence, crude annual mortality rate and standardised mortality ratio (SMR) were calculated. In 2016, the overall crude incidence rate of SSc was 18.5 (95% CI 16.9–20.2) per million per year. Incidence rate was 31.0 (95% CI 28.1–34.1) per million in women, and 4.3 (95% CI 3.2–5.6) per million in men. Peak incidence was observed in the age range 55–69 years. Overall annual prevalence was 306.1 (95% CI 301.1–311.2) per million. Prevalence was 530.8 (95% CI 521.5–540.2) per million in women and 67.8 (95% CI 64.4–71.3) per million in men, with a female to male ratio of 7.8:1. Highest prevalence was observed in the range 70–84 years. Crude annual mortality rate was 27.9 (95% CI 24.9–31.1) per 1000 patients. Overall SMR in patients with SSc was 2.8 (95% CI 1.9–3.8). SMR was 3.8 (95% CI 2.9–5.1) in men and 2.6 (95% CI 1.8–3.6) in women. We provided updated estimates on epidemiology of SSc in Italy. Our findings on incidence, prevalence and mortality of SSc are consistent with previously published literature.