Association between lactate-to-albumin ratio and 30-day mortality in patients with polytrauma: a retrospective study

Background : The lactate-to-albumin ratio (LAR) has recently been proposed as a new prognostic marker for various conditions. However, not many studies have used it to predict the 30-day mortality rate in polytrauma patients. This study aimed to establish a link between the LAR and 30-day mortality in polytrauma patients. Methods : This retrospective cohort study was conducted on 477 adult polytrauma patients admitted to the intensive care unit (ICU) of Jiangsu University Affliated Hospital. To establish the association between the LAR and 30-day mortality in patients in the ICU, multivariate Cox regression and Kaplan-Meier survival analyses were performed. The restricted cubic spline (RCS) curve was used to further explore the association between the LAR and 30-day in-hospital mortality. The predictive ability of various indicators of 30-day in-hospital mortality was evaluated through receiver operating characteristic (ROC) curves, and the area under the curve (AUC) of each indicator was calculated. Subgroup analyses were also performed. Results : Of the 477 polytrauma patients, 101 died after 30 days of hospitalization, giving a 30-day in-hospital mortality rate of 21.17%. The COX regression model revealed a strong association between the LAR (0.26–0.67) and higher mortality [odds ratio (OR) being 1.92 (95%CI: 1.22–2.81)]. The RCS curve revealed a nonlinear relationship between the LAR and 30-day mortality (p <0.001). The 30-day mortality was higher in the 3 ^rd quartile (Q3) group compared to the 1 ^st (Q1) and 2 ^nd (Q2) quartile groups. The log-rank test yielded p <0.001, signifying that the differences in survival curves across the three groups were non-random. The AUCs for the ROC curves of the LAR, lactate, and albumin were 0.859 (95%CI 81.9–90.1), 0.817 (95%CI 77.2–86.2), and 0.707 (95%CI 64.6–76.9), respectively (p <0.001 for all). Subgroup analyses showed no significant interaction between the LAR and different subgroups (p = 0.107–0.876), indicating an association between the LAR and 30-day mortality in polytrauma patients regardless of subgroup differences. Conclusion : The LAR might be the a predictor of 30-day fatality for hospitalized polytrauma patients. Future prospective studies need to verify the predictive value of the LAR on 30-day mortality in polytrauma patients.