Comparison of National Early Warning Score with shock index in patients with necrotizing fasciitis

Shock index (SI) and national early warning score (NEWS) are more frequently used as assessment tools in acute illnesses, patient disposition and early identification of critical condition. Both they are consisted of common vital signs and parameters including heart rate, systolic blood pressure, respiratory rate, oxygen saturation and level of conscious, which made it easy to evaluate in medical facilities. Its ability to predict mortality in patients with necrotizing fasciitis (NF) in the emergency department remains unclear. This study was conducted to compare the predictive capability of the risk scores among NF patients. A retrospective cohort study of hospitalized patients with NF was conducted in 2 tertiary teaching hospitals in Taiwan between January 2013 and March 2015. We investigated the association of NEWS and SI with mortality in NF patients. Of the 395 NF patients, 32 (8.1%) died in the hospital. For mortality, the area under the receiver curve value of NEWS (0.81, 95% confidence interval 0.76-0.86) was significantly higher than SI (0.76, 95% confidence interval 0.73-0.79, P =.016). The sensitivities of NEWS of 3, 4, and 5 for mortality were 98.1%, 95.6%, and 92.3%. On the contrast, the sensitivities of SI of 0.5, 0.6, and 0.7 for mortality were 87.8%, 84.7%, and 81.5%. NEWS had advantage in better discriminative performance of mortality in NF patients. The NEWS may be used to identify relative low risk patients among NF patients.