**4. Conclusions**

The hemogram is an easily measurable, readily available, cost-effective and reliable test that could be very useful in establishing the risk of in-hospital mortality on hospital admission and in guiding therapeutic decisions in patients with COVID-19.

In this sense, the hemogram is a tool available to all healthcare centers that do not have the technical and material means to perform complex immunological studies, which usually involve late results.

The combination of hemogram parameters and blood cell count ratios in COVID-19 patients could be a useful combined indicator of host immune and inflammatory status.

The ratios derived from the hemogram at the time of hospital admission and its increasing trend during the first days of hospitalization have shown their value in identifying patients with COVID-19 who have a worse evolution and could be useful as prognostic markers of the disease.

The NLR and the novelty NPR have been shown to be independent markers of mortality and worse prognosis in patients with COVID-19. These ratios should be included in future prospective studies and it would be advisable to start using them by physicians in the first evaluation of patients with COVID-19 in the emergency department to demonstrate their clinical utility.
