Hematological parameters predicting severity and mortality in COVID-19 patients of Pakistan: a retrospective comparative analysis

Abstract

Background and objectives: COVID-19 is a global pandemic. In our study, we aimed to utilize the hematological parameters in predicting the prognosis and mortality in COVID-19 patients.

Materials and methods: A retrospective, observational study was conducted to include all the admitted patients (n = 191) having COVID-19 Polymerase chain reaction (PCR) positive, and evaluated those for prognosis and disease outcome by utilizing several biochemical and hematological markers.

Results: Amongst the patients admitted in the ward versus in the intensive care unit (ICU), there were significant differences in mean hemoglobin (P = 0.003), total leukocyte count (P = 0.001), absolute neutrophil and lymphocyte counts (P < 0.001), absolute monocyte count (P = 0.019), Neutrophil-to-Lymphocyte ratio (NLR) and Lymphocyte-to-Monocyte ratio (LMR) (P < 0.001), Platelet-to-Lymphocyte ratio (PLR) and Lymphocyte-to C-reactive protein ratio (LCR) (P = 0.002), and C-reactive protein (CRP) levels (P < 0.001). Amongst the deceased patients, there was significant leukocytosis (P = 0.008), neutrophilia and lymphopenia (P < 0.001), increased NLR (P = 0.001), decreased LMR (P < 0.001), increased PLR (p = 0.017), decreased LCR (p = 0.003), and elevated CRP level (P < 0.001). A receiver operating characteristic curve obtained for the above parameters showed NLR (AUC: 0.841, PPV: 83.6%) and PLR (AUC: 0.703, PPV: 81.8%) for ICU patients, while NLR (AUC: 0.860, PPV: 91.1%) and PLR (AUC: 0.677, PPV: 87.5%) for the deceased patients had significant accuracy for predicting the disease severity of COVID-19 in comparison to survivors.

Conclusion: The inflammatory markers and hematological indices are a good guide for predicting the severity and disease outcome of coronavirus disease. NLR and PLR are elevated in severe disease while LMR and LCR are inversely correlating with disease severity.

Keywords: COVID-19; biochemical markers; coronavirus; hematological parameters; indices; infectious disease; intensive care; mortality; pandemic; survivors.