Introduction:
Intensive care unit (ICU) hospitalizations are one of major burdens on the healthcare system, and they may be related to high risk of in-hospital fatality. The aim of the study was to describe long-term trends in ICU hospitalizations and related fatality rates in Poland.

Material and methods:
Our study is a population-based study based on 738,579 ICU hospitalization records in 2012-2021.

Results:
Based on the hospital registry and data on general population, the mean annual ICU hospitalization incidence was estimated at 1.9 per 1,000 (SD: 0.18) and a significant increase trend in hospitalizations was observed from 1.6 per 1,000 in 2012 to 2.2 per 1,000 in 2021, P<0.005. We observed a significant predominance of male patients (56.6% P<0.001) in the study group when compared to general population. The mean and median age in the study group were 61.6 (SD: 18.2) and 65 years (IQR: 53-74), respectively. The trend in fatal hospitalizations increased significantly from 37.7% in 2012 to 46.5% in 2021, P<0.05. However, the trend in fatal hospitalization rates during the ICU stay increased significantly from 31.2% in 2012 to 42.5% in 2021, P<0.01. The mean length of ICU stays increased from 8.7 in 2012 to 10.1 days in 2021, P<0.001.

Conclusions:
The paper presents the recent trends in quantitative and qualitative changes in ICU hospitalizations in Poland. The presented data may be the basis for comparative analyzes in a global context. Reported data may indicate the need to perform adaptive systemic changes to improve health care.