Abstract TP242: Predictive Validity of the Modified World Federation of Neurosurgical Societies Subarachnoid Hemorrhage Grading System (Modified WFNS Scale) for the Outcome of Patients With Aneurysmal Subarachnoid Hemorrhage

Abstract

Introduction: Evaluating the prognosis of aSAH patients who may be at risk of poor outcomes using grading systems is one way to make a better decision on treatment for these patients. This study compared the accuracy of modified WFNS, WFNS, and Hunt and Hess (H&H) scales in predicting the aSAH patient's outcome. Methods: From August 2019 to June 2021, we conducted a multicenter prospective cohort study on aSAH adult patients in three central hospitals in Hanoi, Vietnam. The primary outcome was the 90-day poor outcome, measured by scores of 4-6 on mRS. We calculated areas under the receiver operator characteristic (ROC) curve (AUROCs) to determine how well the grading scales could predict patient prognosis upon admission. We also used ROC curve analysis to find the best cut-off value for each scale. We made comparisons of AUROCs using Z-statistics and compared 90-day mean mRS scores among intergrades using the pairwise multiple-comparison test. Finally, we used logistic regression to identify factors associated with the 90-day poor outcome. Results: Of 415 patients, 32% had a 90-day poor outcome. Modified WFNS (AUROC: 0.839 [95% CI: 0.795-0.883]; cut-off value≥2.50), WFNS (AUROC: 0.837 [95% CI: 0.793-0.881]; cut-off value≥3.5), and H&H scales (AUROC: 0.836 [95% CI: 0.791-0.881]; cut-off value≥3.5) were all good at predicting patient prognosis on day 90th after ictus. However, there were no significant differences between AUROCs of these scales. Only grades IV and V of modified WFNS (3.75±2.46 vs. 5.24±1.68, p=0.026), WFNS (3.75±2.46 vs. 5.24±1.68, p=0.026), and H&H scales (2.96±2.60 vs. 4.97±1.87, p<0.001) showed a significant difference in the 90-day mean mRS scores. In the multivariable models, with the same set of confounding variables, modified WFNS grade of III-V (adjusted OR (AOR): 9.090; 95% CI: 3.494-23.648) was more strongly associated with increased risk of the 90-day poor outcome compared to WFNS grade of IV-V (AOR: 6.383; 95% CI: 2.661-15.310) or H&H grade of IV-V (AOR: 6.146; 95% CI: 2.584-14.620). Conclusions: In this study modified WFNS, WFNS, and H&H scales all had good discriminatory abilities for the prognosis of aSAH patients. Because of better effect size in predicting poor outcomes, the modified WFNS scale seems preferable to the WFNS and H&H scales.