Epidemiological characteristics and outcomes from 187 patients with COVID-19 admitted to 6 reference centers in Greece: an observational study during the first wave of the COVID-19 pandemic

Introduction: Epidemiological data from patients with COVID-19 has been recently published in several countries. Nationwide data of hospitalized patients with COVID-19 in Greece remain scarce. Material and methods: This was an observational, retrospective study from 6 reference centers between February 26 and May 15, 2020. Results: The patients were mostly males (65.7%) and never smokers (57.2%) of median age 60 (95% CI: 57.6-64) years. The majority of the subjects (98%) were treated with the standard-of-care therapeutic regimen at that time, including hydroxychloroquine and azithromycin. Median time of hospitalization was 10 days (95% CI: 10-12). Twenty-five (13.3%) individuals were intubated and 8 died (4.2%). The patients with high neutrophil-to-lymphocyte ratio (NLR) (> 3.58) exhibited more severe disease as indicated by significantly increased World Health Organization (WHO) R&D ordinal scale (4; 95% CI: 4-4 vs 3; 95% CI: 3-4, p = 0.0001) and MaxFiO(2)% (50; 95% CI: 38.2-50 vs 29.5; 95% CI: 21-31, p < 0.0001). The patients with increased lactate dehydrogenase (LDH) levels (>270 IU/ml) also exhibited more advanced disease compared to the low LDH group (< 270 IU/ml) as indicated by both WHO R&D ordinal scale (4; 95% CI: 4-4 vs 4; 95% CI: 3-4, p = 0.0001) and MaxFiO(2)% (50; 95% CI: 35-60 vs 28; 95% CI: 21-31, p < 0.0001). Conclusion: We present the first epidemiological report from a low-incidence and mortality COVID-19 country. NLR and LDH may represent reliable disease prognosticators leading to timely treatment decisions.