The predictive value of red blood cell distribution width/serum albumin ratio for ICU all-cause mortality

Feng Xilian; Zhang Wei; Yang Liuliu

doi:10.3969/j.issn.1002-1949.2025.03.004

Abstract：Objective To investigate the association of red blood cell distribution width/serum albumin ratio(RAR)with all-cause mortality in the intensive care unit(ICU)and the predictive value of RAR.Methods The data of ICU inpatients were extracted from medical information mart for intensive care Ⅲ(MIMIC Ⅲ)medical database.RAR was divided into four intervals by quartile method,and the survival curves of RAR in different intervals were analyzed.Cox regression models combined with restricted cubic spline and subgroup analysis were used to study the association between RAR and ICU all-cause mortality.The P value for interaction of each subgroup was calculated and a forest map was drawn.Receiver operating characteristic(ROC)curve was used to evaluate the predictive performance of RAR.Decision curve analysis(DCA)was used to evaluate the clinical application value.Results A total of 27 473 ICU patients were included in the study.6 738,6 979,6 862 and 6 894 patients fell into the first interval(RAR≤3.51),the second interval(3.51＜RAR≤4.17),the third interval(4.17＜RAR ≤5.21)and fourth interval(RAR＞5.21),respectively.In the Cox regression model adjusted for different confounding variables,the RAR was an independent risk factor for all-cause mortality in ICU.The restricted cubic spline showed a non-linear association between RAR and all-cause mortality in ICU.The area under the ROC curve(AUC)was 0.707 1,which was higher than the AUC of the red blood cell distribution width(RDW,AUC=0.651 8).DCA showed that RAR had clinical application value.The results of subgroup analysis showed that the P for interaction was less than 0.05 in the cardiac surgery recovery unit(CSRU),surgical intensive care unit(SICU)and trauma-surgical intensive care unit(TSICU).The hazard ratio(HR)and 95％confidence interval(CI)of the CSRU,SICU and TSICU were 1.53(1.43-1.63),1.06(1.01-1.11)and 1.02(0.96-1.09),respectively.Conclusions RAR is an independent risk factor for ICU all-cause mortality,which has predictive significance for ICU all-cause mortality,but has no value in TSICU.