Platelet-to-white Blood Cell Ratio: A Feasible Predictor for Unfavorable Functional Outcome in Patients with Aneurysmal Subarachnoid Hemorrhage

This study aimed to identify the association between the platelet-to-white blood cell ratio (PWR) and outcomes in patients with aneurysmal subarachnoid hemorrhage (aSAH). Data for patients diagnosed with aSAH and admitted from January 2015 to December 2020 were retrospectively analyzed. Multivariate logistic regression analysis was performed to identify factors that correlated with unfavorable outcomes at 3 months. Receiver operating characteristic (ROC) curve analysis was used to determine the optimal cut-off value for the PWR to discriminate favorable and unfavorable outcomes at 3 months. The patients were then divided into two groups based on this cut-off value. To reduce selection bias, propensity score matching (PSM) was performed to balance the baseline characteristics. In total, 800 patients were enrolled in this study. The multivariate logistic regression analysis showed that the PWR (odds ratio, 1.05; 95% confidence interval, 1.00-1.09; p = 0.034) at admission was independently associated with unfavorable 3-month outcomes. ROC curve analysis identified 15.69 as the best cut-off PWR value for predicting clinical outcomes. After PSM, patients with a PWR < 15.69 exhibited a higher incidence of postoperative pneumonia (POP) (37.2% vs. 25.6%, p = 0.011) and unfavorable 3-month outcomes (19.3% vs. 12.1%, p = 0.043). These findings suggest that patients with aSAH showing a PWR < 15.69 at admission have a higher probability of developing POP, which may be the main factor causing unfavorable outcomes at 3 months.