The predictors of prognostic nutritional index and its association with in-hospital mortality among critically ill geriatric patients

<b>Purpose:</b> The study aimed to determine the predictors of prognostic nutritional index (PNI) and its association with in-hospital mortality among critically ill geriatric patients<br /> <b>Materials and methods:</b> Prospective cohort study included 113 critically ill older patients at a geriatrics hospital in Egypt. Clinical history, laboratory analyses, Charlson comorbidity index, and simplified acute physiology score II were conducted on admission. Immuno-nutritional biomarkers included PNI, neutrophil/lymphocyte ratio (NLR), systemic immune inflammation index (SII), and platelet/lymphocyte ratio (PLR). The hospital outcome was in-hospital mortality.<br /> <b>Results:</b> Median PNI was 33.45. Predictors of PNI were albumin and hematocrit. PNI showed a negative correlation with<b> </b>NLR (r = -0.475, p < 0.001), PLR (r = -0.263, p = 0.005), and SII (r = -0.287, p = 0.002). PNI < 35.475 and NLR > 6.5 defined in-hospital mortality with an area under the curve of 0.633, p = 0.011 and p = 0.612, p = 0.036, respectively.<br /> <b>Conclusion:</b> PNI < 35.475 and NLR > 6.5 are associated with in-hospital mortality. PNI had an inverse correlation with NLR, SII, and PLR.