Prognostic value of neutrophil to lymphocyte ratio in infection with COVID-19 virus - A retrospective study

Background: The spread of COVID-19 infection paved way to many admissions into hospitals worldwide exhausting the healthcare systems. A simple test for immediate stratification of risk in patients with infection by COVID 19 virus is important. Aim in this study was to know the prognostic value of neutrophil to lymphocyte ratio (NLR) in determination of the severity of infection in COVID-19 infected patients. Methods: This study was conducted in a tertiary care institute, Mandya. Clearance from Institutional Ethical committee was taken. Data from 108 COVID-19 infected hospitalized patients between April 2021 and June 2021 were collected retrospectively from hospital records. Patients in the study were grouped into two groups as Intensive Care Unit (ICU) and Ward (Non ICU) patients, based on admission into ICU. The patient’s demographic characteristics, comorbidities, clinical manifestations, medications used and investigations done initially during admission were noted from the hospital files for both groups. Chi-square test/ Fisher's exact test was used for comparison of categorical outcomes. Statistical significance was noted if P value < 0.05. Results: Of 108 patients, 25 patients (23.15%) had ICU admission. Patients aged >55years had more ICU admission (44%) than non-ICU admissions (22.89%). In patients <55years non-ICU admissions were more (77.11%) compared to ICU admissions (56%). Leukocytosis, neutrophilia, lymphopenia, high CRP values were seen more in patients in ICU than in ward and is significant statistically (p <0.05). High NLR values were seen in patients in ICU than in ward. Chi-square test is significant (p < 0.05). Conclusion: Increased NLR predicts the severity of infection in patients infected with COVID-19 virus, who will require admission into ICUs. It can be used as a biomarker which can aid in identifying severe COVID 19 infection.