This observational study aims to determine whether three blood test ratios - lactate-to-albumin, CRP-to-albumin, and procalcitonin-to-albumin - can predict in-hospital mortality among critically ill adults. The study includes all adult patients admitted in 2024 to the ICU Ward B at the Silesian Center for Heart Diseases (SCCS) in Zabrze. Researchers will analyze retrospective clinical and laboratory data from electronic medical records, including lab values collected at ICU admission, patient demographics, diagnoses, and outcomes. The biomarker ratios will be manually calculated in Excel and statistically evaluated. The main goal is to assess whether these ratios are associated with patient survival and to identify predictive cut-off values to support early risk stratification in the ICU setting.

Inclusion Criteria:

• Age ≥ 18 years
• Admission to ICU in 2024
• Availability of data for lactate, CRP, procalcitonin, and albumin

Exclusion Criteria:

• Missing outcome data (e.g. unknown survival status)
• Lack of laboratory parameters necessary for ratio calculation

Adult patients admitted to the ICU. Data collected retrospectively from clinical records (AMMS system).

The individual participant data (IPD) will not be shared due to the retrospective nature of the study and the use of sensitive patient health records. The dataset is not publicly available, and consent for external data sharing was not obtained from participants or their legal representatives.