Sarcoidosis among hospitalized patients in Poland: a study based on a national hospital registry.

INTRODUCTION Sarcoidosis is a systemic granulomatous disease mainly affecting the lungs, although granulomas can also involve any other organ. OBJECTIVES We sought to describe patients during their first hospitalization for sarcoidosis in Poland from 2008 to 2015. To our knowledge, this is the first evaluation of the disease in Poland based on a hospital morbidity database. PATIENTS AND METHODS We conducted a retrospective, population‑based study, using hospital discharge records compiled by the National Institute of Public Health in the years 2008 to 2015. RESULTS Among the 23 097 patients included in the study, men were predominant (54.7%). The mean and median ages at hospitalization were 44.7 years (95% CI, 44.5-44.9) and 42 years, respectively. Most patients (65%) resided in urban areas. The average annual incidence rate of sarcoidosis was 7.5 per 100 000 (95% CI, 7.1-7.9). The lungs were the most commonly affected organ (57.9%), while the remaining cases included sarcoidosis of lymph nodes and no lung involvement (18%), the skin (1.4%), and other or unspecified sites (22.7%). Skin sarcoidosis occurred significantly more frequently in women, while sarcoidosis of the lungs with coexisting sarcoidosis of lymph nodes was significantly more prevalent in men. Seasonal variability in sarcoidosis incidence was observed. CONCLUSIONS Sex and age may have a significant impact on the occurrence of sarcoidosis in Poland. Changes in seasonality may suggest the role of environmental factors. These data on sarcoidosis in Poland may be helpful in comparative analyses with other European countries.