Kong T, et al. - In this retrospective analysis, researchers assessed the clinical utility of the delta neutrophil index (DNI) as a marker of severity in patients presenting to Emergency Department (ED) with acute pulmonary embolism (PE), focusing on all-cause mortality within 28 days of ED admission. No additional burdens of cost or time were imposed by determination of DNI value, obtained as part of the complete blood count analysis. Instead, it could be easily determined. As observed, 3.0% was the optimal cut-off DNI value, measured on ED admission. The documented association of this value with an increased hazard of 28-day mortality following PE indicated the utility of a high DNI as a marker to predict 28-day mortality in patients with acute PE.