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
