en Other Other Original article Original article <div style="text-align: justify;"><b><span style="font-size:10.0pt"><span style="line-height:107%"><span new="" roman="" style="font-family:" times="">Introduction:</span></span></span></b><span style="font-size:10.0pt"><span style="line-height:107%"><span new="" roman="" style="font-family:" times=""> Rapid and accurate diagnosis of COVID-19 is critical for effective patient management, timely treatment, and mitigating disease transmission. Identifying reliable prognostic markers, such as hematological indices, can enable prompt medical intervention and improve outcomes. This study aimed to investigate the association among mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), and mean corpuscular volume (MCV), measured within the first 10 days of hospital admission, and clinical outcomes (<i>e.g</i>., survival <i>vs</i>. mortality) in COVID-19 patients. <b>Methods:</b> This retrospective study included 173 patients with confirmed COVID-19 (Delta variant) admitted to Taleghani Hospital in Urmia. Complete blood count (CBC) data, including hemoglobin (Hb), mean corpuscular hemoglobin (MCH), mean corpuscular volume (MCV), and white blood cell (WBC) counts, were extracted from electronic medical records. Differences between survivor and non-survivor groups were analyzed using ANOVA with Tukey post hoc test, with statistical significance set at <i>P</i> < 0.05.<b> Results:</b> The median age of all patients was 53 years (IQR: 22&ndash;88), with a significant difference between survivors (52 years; IQR: 22&ndash;88) and non-survivors (60 years; IQR: 35&ndash;85) (<i>P</i> = 0.04). Patients in the non-survivor group had a significantly higher prevalence of comorbidities compared to the survivor group. Patients with diabetes (<i>P</i>=0.327) or hypertension (<i>P</i>=0.797) did not have a significantly higher prevalence in the non-survivor group, though trends suggest possible increased mortality risk. However, no significant differences were found in Hb, MCH, and MCV between the survivor and non-survivor groups (<i>P</i>>0.05).<b> Conclusions:</b> While some hematological markers are routinely used in diagnosing various diseases, this study did not find significant differences in Hb, MCH, and MCV between survivor and non-survivor groups, suggesting these specific markers may not be reliable for early diagnosis or predicting prognosis in Delta-variant COVID-19 in this Iranian cohort. Further research with a larger sample size and including a wider range of hematological and inflammatory markers is warranted to explore the potential role of these markers in COVID-19 diagnosis and prognosis. Investigating the interplay between these markers and clinical outcomes could provide valuable insights for patient management.</span></span></span></div> &nbsp; COVID-19, Prognosis, Hematological indices, Early diagnosis, Hospitalized patients, Mean corpuscular volume, Mean corpuscular hemoglobin 224 230 http://jommid.pasteur.ac.ir/browse.php?a_code=A-10-576-1&slc_lang=en&sid=1 Sahar Mehranfar saharmehranfar85@gmail.com 0000-0001-7831-7102 No Department of Genetics and Immunology, Urmia University of Medical Sciences, Urmia, Iran Ali Yekanlou aliyekanlou@gmail.com 0000-0002-6360-9409 No Student Research Committee, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran Mohammad Heidari Heidari.m1358@gmail.com No Department of Epidemiology and Biostatistics, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran Masoud Lahouty masoud.lahouty@gmail.com 0000-0003-2302-2192 Yes Department of Microbiology and Virology, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran