The prognostic value of platelet-to-lymphocyte ratio on in-hospital mortality in admitted adult traffic accident patients

BACKGROUND: The predictive value of platelet-to-lymphocyte ratio (PLR) in acute illness is well known, but further evaluation is needed in traffic accident patients. METHODS: This retrospective observational study enrolled consecutive adult patients involved in traffic accidents who were admitted to the study hospital’s emergency department during 1 year. The initial platelet and lymphocyte counts after arrival at the emergency department were the variables of interest. The primary outcome was in-hospital mortality. Data on baseline characteristics, comorbidities, and physiological and laboratory variables were collected. Multivariate Cox proportional hazard modelings were used to identify the variables independently associated with the outcome. RESULTS: A total of 1,522 traffic accident patient were screened, and 488 patients were enrolled. In all, 43 (8.8%) patients died in the hospital. The median PLR was 115.3 (interquartile range 71.3;181.8). The in-hospital mortality rate of the 1(st) tertile of PLR (21.5%) was significantly higher than the rates of the 2(nd) (2.5%) and 3(rd) (2.5%) tertiles. The area under the receiver operating characteristic curve of PLR for in-hospital survival was 0.82 (95% confidential interval [CI], 0.74–0.89), which was greater than that of lymphocyte count (0.72; 95% CI 0.63–0.81) and platelet count (0.67; 95% CI 0.57–0.76). The Kaplan-Meier curves showed a significant difference in survival between the tertiles (p<0.001). The Cox regression model showed that the 2(nd) tertile of PLR was independently associated with lower in-hospital mortality (adjusted hazard ratio 0.30; 95% CI, 0.09–0.98), compared to the 1(st) tertile. CONCLUSION: PLR was significantly associated with an increased risk of in-hospital mortality in admitted adult traffic accident patients.