Adult-onset Still's disease in Poland - a nationwide population-based study

Adult-onset Still's disease (AOSD) is a rare systemic inflammatory disorder of unknown etiology, which affects young adults and is associated with multiple organ involvement and life-threatening complications. The aim of the study was to establish the incidence and prevalence of AOSD in Poland, and factors related to this disease among hospitalized patients.

A retrospective, population-based study was conducted, using data from hospital discharge records compiled by the National Institute of Public Health in 2009-2018.

Based on hospitalization records and census data in a group of the 1,050 patients included in the study, women were predominant (60%) and patients' mean and median ages at hospitalization were 42 (95% CI: 40.8-42.8) and 38 years, respectively. The average annual incidence rate of AOSD during the 10-year period was established at the level of 0.32/100,000 (95% CI: 0.30-0.34), and the point prevalence at the end of 2018 was 2.7/100,000. The most common comorbidities were: cardiovascular diseases (14%), diseases of the musculoskeletal system and connective tissue (14%), endocrine, nutritional and metabolic diseases (9%).

AOSD is a rare disease Poland with gender and territorial differences in incidence ratek, and predominance of cardiovascular diseases among comorbidities. The presented data may be useful for comparisons of the Polish population with other geographical regions. Predominance of patients from urban regions and predominance of women may suggest environmental and personal factors in AOSD development; however, further research seems to be necessary.