RESUMEN
INTRODUCTION: This study aims to research the effects of hematological and inflammatory parameters on the prognosis of COVID-19 disease and hospitalization duration. METHODOLOGY: One hundred and eighty-six patients with COVID-19 and a control group consisting of 187 healthy individuals were included in the study. Hematological variables and inflammatory parameters of the patients were recorded on the first and the fifth days of hospitalization. RESULTS: White blood cell count, lymphocyte count, and platelet count were statistically lower, and mean platelet volume (MPV), neutrophil to lymphocyte ratio (NLR), and platelet to lymphocyte ratio (PLR) levels were higher in the patient group compared to the control group. It was observed that the neutrophil count and MPV level were lower, and the platelet count and ferritin level were statistically higher on the fifth day of follow-up compared to the admission day. In contrast, there was a significantly positive correlation between the duration of hospitalization and the fifth day D-dimer (r = 0.546, p < 0.001) and ferritin (r = 0.568, p < 0.001); in addition, there was a negative correlation between the duration of hospitalization and admission day lymphocyte count and the fifth-day lymphocyte count. CONCLUSIONS: Increased levels of ferritin and D-dimer, and decreased count of lymphocytes are among the important factors affecting the duration of hospitalization for COVID-19 patients. Furthermore, we think that neutrophil count and MPV levels are low, and platelet count and ferritin levels are high during the disease. Therefore, these parameters can be used as prognostic indicators of the disease.