A Retrospective Cohort Study on the Association between Red Cell Distribution Width and All-Cause Mortality of Patients with Cholecystitis at ICU Admission

BACKGROUND: Elevated red cell distribution width (RDW) has been reported to be associated with mortality in some critically ill patient populations. The aim of this article is to investigate the relationship between RDW and in-hospital mortality and short- and long-term mortality of patients with cholecystitis. METHOD: We conducted a retrospective cohort study in which data from all 702 patients extracted from the Medical Information Mart for Intensive Care III (MIMIC-III) database were used. Receiver operating characteristic (ROC) curves were constructed to evaluate the prognostic predictive value of RDW for in-hospital mortality and short- (i.e., 30-day and 90-day) and long-term (i.e., 180-day, 1-year, 3-year, and 5-year) mortality. We converted RDW into a categorical variable according to quintiles as less than or equal to 13.9%, 14.0-14.8%, 14.9-15.8%, and 15.9-17.2% and more than 17.2%. The Kaplan-Meier (K-M) methods and log-rank tests were used to compare survival differences among different groups. The relationships between RDW levels and in-hospital mortality were evaluated by univariate and multivariate binary logistic regression models. Multivariable Cox regression models were built to investigate the association of RDW on the short-term and long-term mortality. RESULT: After adjusting for potential confounders, RDW was positively associated with in-hospital mortality (OR: 1.187, 95% CI [1.049, 1.343]) and short- (i.e., 30-day: HR: 1.183, 95% CI [1.080, 1.295], 90-day: HR: 1.175, 95% CI [1.089, 1.268]) and long-term (i.e., 1-year: HR:1.162, 95% CI [1.089, 1.240]) mortality in critically ill patients with cholecystitis. Similar results were also shown in the secondary outcomes of 180-day, 3-year, and 5-year mortality. RDW had a significant accurate prognostic effect on different endpoints and could improve the prognostic effect of scoring systems. CONCLUSION: High level of RDW is associated with an increased risk of in-hospital mortality and short- and long-term mortality in critically ill patients with cholecystitis. RDW can independently predict the prognosis of patients with cholecystitis.