Combined Effect of White Blood Cell and Platelet Count for Predicting In-Hospital Mortality and Pneumonia in Acute Ischemic Stroke

Abstract Background: High white blood cell (WBC) count was the risk factors for mortality and pneumonia after acute ischemic stroke (AIS). Low platelet count increased the risk of mortality. We investigated the combined effect of WBC count and platelet count on hospital admission and in-hospital mortality and pneumonia in acute AIS patients.Methods: A total of 3,265 AIS patients enrolled from December 2013 to May 2014 across 22 hospitals in Suzhou city were included in the present study. We divided patients into four groups according to their level of WBC count and platelet count: LWHP (low WBC and high platelet), LWLP (low WBC and low platelet), HWHP (high WBC and high platelet) and HWLP (high WBC and low platelet). Cox proportional logistic regression model were used to estimate the combined effect of WBC count and platelet count on all cause in-hospital mortality and pneumonia in AIS patients. Results: HWLP was associated with a 2.07-fold increase in the risk of in-hospital mortality in comparison to LWHP (adjusted odds ratio [OR] 2.07; 95% confidence interval [CI], 1.02-4.18; P-trend =0.020). The risk of pneumonia was significantly higher in patients with HWLP compared to those with LWHP (adjusted OR 2.29; 95% CI, 1.57-3.35; P-trend <0.001). The C-statistic for the combined WBC count and platelet count was higher than WBC count or platelet count alone for prediction of in-hospital mortality and pneumonia (all p < 0.01). Conclusions: High WBC count combined with low platelet count level at admission was independently associated with in-hospital mortality and pneumonia in AIS patients. Moreover, the combination of WBC count and platelet count level appeared to be a better predictor than WBC count or platelet count alone.