Incidence and prevalence of Systemic Sclerosis (SSc) in Poland - differences between rural and urban regions

Introduction. Systemic sclerosis (SSc) is a rare and potentially severe connective tissue disease, characterized by skin fibrosis and involvement of internal organs. Because of its rarity and heterogeneous clinical presentation, reliable epidemiological studies on SSc have been particularly difficult to carry out. Objectives. The purpose of this study was to present SSc epidemiology among hospitalized patients in Poland. Materials and method. The analysis was based on population-based administrative data, taken from a Polish hospital morbidity study carried out by the National Institute of Public Health between January 2008 – December 2012. Results. Analyzed data covered 9,049 hospitalization records. The final sample comprised 3,653 patients with first-time hospitalizations for SSc. The average age of the sample was 53 years (SD 16.2; range 0–91 years); 84% of patients were female and 16% male. Based on hospitalization registers, the average SSc incidence was estimated to be 1.9/100,000 per year and peak age of incidence was 55 years. The point prevalence was estimated to be 9.4/100,000 at the end of 2012. SSc was more common in females, with F:M ratio ranging from 6.2:1–4.6:1 depending on the year. Analysis of hospitalization trends revealed that overall numbers of SSc hospitalizations increased, while first-time hospitalizations decreased between 2008–2012. Clusters of higher incidence were observed in more rural regions vs. urban regions. Conclusion. Estimated incidence of SSc in Poland was comparable to reported incidence in other European countries. Analysis of demographic factors and reports of clusters of higher incidence may suggest the existence of environmental risk factors for the development of SSc. These observations may require further research