Surprisingly low C-reactive protein levels in the hospital sudden death statistics. A retrospective Polish single-center analysis

Identifying patients at high risk of in-hospital mortality within the early days of admission is crucial for guiding medical decisions and allocating resources effectively. This study aimed to explore whether changes in routinely conducted in-hospital admission tests were associated with sudden death among patients (all causes) in the Regional Hospital in Racibórz, Poland. The first laboratory tests of ten biomarkers from 7,827 unique patients were examined, from January 1 to December 31, 2023. Associations between risk factors and all-cause sudden death outcomes were estimated using Cox regression. Based on the estimated concordance statistic, C-reactive protein, among other biomarkers, showed the best fit in the model. Its values were categorized following the interquartile ranges and death rates for each range were modeled using Poisson regression. Despite acknowledging all other possible causes that may have contributed to the early deaths of patients, a surprisingly low and statistically significant (p < 0.05) CRP threshold of 7.4 mg/L was found to differentiate 30-day mortality in patients. Regarding patient deaths, the estimates for hospital wards align with expectations, indicating that an elevated mortality risk was observed in the Intensive Care Unit and Internal Medicine Ward compared to the Emergency Department. The study results shed new light on CRP significance, suggesting the need for further research and verification.