Tehran University of Medical Sciences Frontiers in Emergency Medicine 2717-3593 5 1 2020 07 19 e8 e8 EN Mustafa Eid Department of Emergency Medicine, Al Ain Hospital, Al Ain, UAE. Maythem Al-Kaisy Department of Emergency Medicine, Al Ain Hospital, Al Ain, UAE. Walaa Regeia Department of Emergency Medicine, Al Ain Hospital, Al Ain, UAE. Hakimuddin Jiwa Khan Department of Emergency Medicine, Al Ain Hospital, Al Ain, UAE. 2020 06 13 2020 07 14 Introduction: COVID-19 is a newly emerging pandemic viral disease. Multiple management guidelines were introduced; nevertheless, their efficacy is still under debate. Thus, the presences of prognostic factors are essential for predicting which patients will need more invasive treatments. Objective: The study aims to investigate the prognostic accuracy of neutrophil-lymphocyte ratio in COVID-19 infection. Methods: This is a prospective study done in Al-Ain Hospital in the United Arab Emirates. All the Covid-19 patients presenting to the hospital were enrolled over 1 month from 20/3 to 20/4/2020. We gathered information about their age, sex, mode of transmission, and calculated their Neutrophils/Lymphocytes ratio (NLR) from the first complete blood picture on admission. We divided the patients into two groups: those whose age was 50 years and above and the those aged less than 50 years. We chose the best NLR cut-off value based on the Youden index and receiver operating characteristic (ROC) curve analysis and the target endpoint was presence or absence of intensive care unit (ICU) admission. Results: The study revealed that 48 patients (14%) needed ICU admission, while 296 patients (86%) were admitted to a ward or quarantine facilities. When the patient's age was > 50, and NLR was ≥ 3.10, it showed a sensitivity of 95.24% and a specificity of 92.86% for predicting the need for ICU admission. When NLR was ≥ 4.21, and the patient's age was < 50, the sensitivity and specificity were 70.3% and 93.7%, respectively. Conclusions: NLR proved to be highly specific and sensitive in helping to identify patients who need more invasive care among people over 50 years of age with COVID-19. https://fem.tums.ac.ir/index.php/fem/article/view/472 https://fem.tums.ac.ir/index.php/fem/article/download/472/318