Association between phosphorus‐to‐calcium ratio at ICU admission and all‐cause mortality in acute pancreatitis: Insights from the MIMIC‐IV database

BACKGROUND: Serum phosphorus and serum calcium are important electrolytes in the body. The relationship between them and acute pancreatitis (AP) has been previously discussed. However, the results seem to lack credibility due to the neglect of mutual influence between them. Thus, a comprehensive indicator is needed. METHODS: In this study, AP patients with intensive care unit (ICU) treatment were extracted from Medical Information Mart for Intensive Care (MIMIC) database. The outcomes included in-hospital mortality and ICU mortality. Kaplan-Meier survival analysis, Cox proportional hazard regression model and restricted cubic spline were employed to investigate the association between the phosphorus-to-calcium ratio (PCR) index and clinical outcomes. RESULTS: A total of 719 AP patients (57.2% male) were enrolled. The in-hospital and ICU mortality were 11.4% and 7.5%, respectively. After adjusting for confounders, Cox proportional hazard analysis indicated patients with a higher PCR index had a significant association with in-hospital mortality (adjusted hazard ratio, 2.88; 95% confidence interval, 1.34-6.19; p = .007). Restricted cubic splines revealed that a progressively increasing risk of all-cause mortality was associated with an elevated PCR index. CONCLUSION: The PCR index has a strong correlation with in-hospital and ICU all-cause mortality in AP, which provides a reference for clinical decision-making.