Abstract Background and aims This meta-analysis evaluates the prognostic value of admission neutrophil-to-lymphocyte ratio (NLR) in predicting functional outcome, intracranial hemorrhage (ICH), and mortality in patients with acute ischemic stroke (AIS). Methods We searched in PubMed, Scopus, Web of Science, Cochrane CENTRAL, and Embase until December 17, 2024. Studies examining admission NLR as a predictor for functional outcome, ICH, and mortality in AIS patients were included. A meta-analysis was performed using pooled odds ratios (ORs) with 95% confidence intervals (CIs). Subgroup analyses were conducted based on treatment modality, measurement duration or time of measurement to occur, hemorrhage type, and ethnicity. Heterogeneity was assessed using I2 statistics, and publication bias was evaluated using Egger’s test. Results Sixty studies comprising 33,049 patients were included. Higher admission NLR significantly predicted unfavorable functional outcome (OR: 1.10, 95% CI: 1.07, 1.14, P 0.00001), ICH (OR: 1.06, 95% CI: 1.03, 1.09, P 0.0001), and mortality (OR: 1.06, 95% CI: 1.04, 1.08, P 0.00001). Subgroup analysis indicated that NLR predicted poor outcome in AIS patients receiving mechanical thrombectomy (MT) and intravenous thrombolysis (IVT). Ethnicity-based analysis showed stronger associations in Asian populations. Conclusions Admission NLR is a significant predictor of unfavorable functional outcome, ICH, and mortality in AIS patients. Its predictive value is consistent across different treatment modalities and ethnicities. Given its accessibility and cost-effectiveness, NLR holds promise as a routine biomarker for stroke prognosis. Future research should focus on establishing standardized NLR cut-off values and integrating NLR into multimodal predictive models to enhance clinical decision-making. Conflict of interest Abdallah Abbas: nothing to disclose, Haneen Sabet: nothing to disclose, Dina Essam Abo-elnour: nothing to disclose, Mohammed Tarek Hasan: nothing to disclose, Ahmed Elshahat: nothing to disclose, Ahmed Samir: nothing to disclose, Moaz Elsayed Abouelmagd: nothing to disclose, Ahmed Mostafa Amin: nothing to disclose, Ahmed Mansour: nothing to disclose, Hadir Mustafa Mohamed: nothing to disclose, Rana Ahmed Youssef: nothing to disclose, Ahmed Elmashad: nothing to disclose, Iman Moeini Naghani: nothing to disclose, Sauson Soldozy: nothing to disclose, Amr Elshahat: nothing to disclose, Mostafa Meshref: nothing to disclose, Mohamed Elfil: nothing to disclose, Gurmeen Kaur: nothing to disclose, Chirag D Gandhi: nothing to disclose, Fawaz Al-Mufti: nothing to disclose. Table 1 - belongs to Results
Abbas et al. (Fri,) studied this question.