Can prognostic nutritional index and systemic immune-inflammatory index predict disease severity in COVID-19?

ABSTRACT

BACKGROUND: Prognostic nutritional index (PNI) and systemic immune-inflammatory index (SII) are inflammation-based novel markers that predict the prognosis in various patient populations. We have investigated the relationship between the disease severity in COVID-19, and the PNI and SII scores in the present study. MATERIALS AND METHODS: This cross-sectional retrospective study included 118 hospitalised patients with a confirmed diagnosis of COVID-19. The patients were divided into two groups as those who were hospitalised at the intensive care unit (ICU) and those who had been internalised at the clinic (non-ICU). RESULTS: Of the 118 patients, 50.8% were male. The mean age was 57.7 ± 17.5 years in non-ICU patients and 70.3 ± 11.7 years in ICU patients and the difference was statistically significant (P < .001). The lymphocyte count and the albumin levels were significantly lower in ICU patients (P < .001, P < .001, respectively). The PNI score was significantly lower in ICU patients compared with non-ICU patients (P < .001). The SII score was found to be significantly higher in ICU patients compared with non-ICU patients (P < .001). The value of PNI and SII scores in prediction of the disease severity in COVID-19 was evaluated with the ROC analysis (PNI AUC = 0.796, 95%CI 0.715-0.877, P < .001; SII AUC =0.689, 95% CI 0.559-0.819, P=.004). When the cut-off value was taken as ≤36.7 for the PNI score, it was found to have 73.4% sensitivity and 70.8% specificity for predicting of the disease severity and ICU admission probability was 4.4 times higher. When the cut-off value was taken as ≥813.6 for SII score, it was found to have 70.8% sensitivity and 66.0% specificity for predicting of the disease severity and ICU admission probability was six times higher. CONCLUSION: The PNI and the SII scores are independent predictors of the prognosis and the disease severity in COVID-19 patients who require hospitalisation at the ICU.