Abstract:
Objective To investigate the clinical value of the white blood cell to platelet ratio (WBC/PLT) in assessing the early prognosis of patients with community-acquired pneumonia (CAP) in the emergency department.
Methods A total of 128 patients with CAP admitted to the Emergency Department of Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, from January 2023 to December 2024, were studied retrospectively. Patients were divided into a survival group (n=107) and a non-survival group (n=21). Differences in the WBC/PLT ratio and other clinical biochemical indicators within 24 hours of admission were compared. A logistic regression model was employed to analyze risk factors associated with mortality. Receiver operating characteristic (ROC) curves were generated, and the area under the curve (AUC) was used to evaluate the predictive value of various indicators for mortality.
Results The mean age of the 128 CAP patients was (72.45 ± 17.12) years. The non-survival group had a significantly higher proportion of patients with sepsis, respiratory failure, and use of vasoactive drugs (P < 0.05). Compared to patients in the survival group, the patients in the non-survival group had significantly higher white blood cell counts, urea nitrogen, creatinine levels, and CURB-65 scores, and significantly lower platelet counts (all P < 0.05). The median WBC/PLT ratio in the non-survival group was 0.10 (0.09, 0.15), significantly higher than the 0.03(0.02, 0.04) in the survival group (P < 0.05). Multivariate logistic regression analysis revealed that for each unit increase in WBC/PLT ratio, the risk of patient mortality increased to 1.520 times the baseline; for each additional year of age, mortality risk increased to 1.178 times the baseline; and for each unit increase in oxygenation index, mortality risk decreased to 0.954 times the baseline (all P < 0.05). ROC curve analysis demonstrated that the AUC of the WBC/PLT ratio in predicting mortality was 0.962 (P < 0.001). At the optimal Youden index (0.878), the sensitivity was 95.2% and the specificity was 92.5%.
Conclusions The WBC/PLT ratio was significantly associated with the prognosis of CAP patients and may serve as a guiding significance for the early identification of high-risk patients.