Letter: White Blood Cell Count Improves Prediction of Delayed Cerebral Ischemia Following Aneurysmal Subarachnoid Hemorrhage.

Abstract

To the Editor: We recently read an article carefully in Neurosurgery, “White Blood Cell Count Improves Prediction of Delayed Cerebral Ischemia Following Aneurysmal Subarachnoid Hemorrhage,” written by Fawaz Al-Mufti et al.1 They concluded that an elevated white blood cell (WBC) count >12.1 × 109/L in the first 72-h period after aneurysmal subarachnoid hemorrhage (aSAH) is related to the possibility of delayed cerebral ischemia (DCI) and may be a predictive factor for good-grade (World Federation of Neurological Surgeons [WFNS[ grade < 3) patients, for whom an elevated WBC count may save cost in the diagnosis and treatment. But we find a statistical drawback. In the paper, the author can find obvious confounders in Table 1, including pneumonia (P = .001) and pulmonary edema (P < .001), which all can elevate the WBC count in the first 72 h after admission and influence the validity and authenticity of conclusion. However, they do not analyze those confounders further in grouping, and in a multivariable model, they do not exclude them either. So, we cannot be sure that the patients in the good-grade group are free from these confounding factors. Therefore, the conclusion may be not reliable, although they make a statement in limitations. Disclosures The authors have no personal, financial, or institutional interest in any of the drugs, materials, or devices described in this article.