The role of the neutrophil-lymphocyte ratio in predicting poor outcomes in COVID-19 patients.

Background: This study examines how the neutrophil-lymphocyte ratio (NLR) predicts coronavirus disease 2019 (COVID-19) hospitalization, severity, length, and mortality in adult patients.

Methods: A study was done using a retrospective, single-center, observational design. A total of 400 patients who were admitted to the Ziv Medical Center (Safed, Israel) from April 2020 to December 2021 with a confirmed diagnosis of COVID-19 through RT-PCR testing were included in the analysis. Two complete blood count laboratory tests were conducted for each patient. The first test was administered upon admission to the hospital, while the second test was conducted prior to the patient's discharge from the hospital or a few days before their death.

Results: Four hundred patients were included in the study, 206 males (51.5%) and 194 females (48.5%). The mean age was 64.5 ± 17.1 years. In the group of cases, there were 102 deaths, and 296 survivors were recorded, with a fatality rate of 25.5%. The median NLR was 6.9 ± 5.8 at the beginning of hospitalization and 15.1 ± 32.9 at the end of hospitalization (p < 0.001). The median length of hospital stay was 9.4 ± 8.8 days. NLR in the fatality group was 34.0 ± 49.9 compared to 8.4 ± 20.4 in the survivor group (p < 0.001). Comparison between the NLR at the time of admission of the patient and before discharge/death was 6.9 ± 5.8 vs. 15.1 ± 32.9 (p < 0.001).

Conclusions: The analyses conducted revealed a statistically significant correlation between the NLR and the severity, mortality rates, and the duration of hospitalization. The consideration of NLR should commence during the initial phases of the disease when assessing individuals afflicted with COVID-19.