Performance of CT-based low skeletal muscle index, low mean muscle attenuation, and bioelectric impedance derived low phase angle in the detection of an increased risk of nutrition related mortality

Summary Background & aims The aim of this study was to evaluate in a head to head comparison the performance of bioimpedance derived low phase angle (PA), CT-based low skeletal muscle index (SMI) and low mean muscle attenuation (MA), and Pandora Score (PS) to detect an increased nutrition related mortality in hospitalized patients. Methods A total of 7736 patients were hospitalized in Dessau community hospital (Nov 11, 2016–Feb 05, 2017). In 227/7736 patients an abdominal CT scan was obtained and low values (below threshold) of skeletal muscle index (SMI) and mean muscle attenuation (MA) were obtained at L3 level using Slice-O-Matic. In 180/227 patients, malnutrition screening (NRS-2002 ≥ 3), determination of low PA ( Results PA was low in 116 (64%), SMI was low in 95 (53%), and MA was below threshold in 137 (77%) patients. Using hospital mortality (8.3%) as a gold standard, low SMI, low MA, or low PA showed high sensitivity (SMI 93.3%; MA 86.7%; PA 86.7%) and high negative predictive (NPV) values (SMI 98.9%; MA 95.3%; PA 96.9%) and improved specificity (NRS + SMI 65.5%; NRS + MA 50.3%; NRS + PA 50.3%) when combined with the criterion NRS ≥ 3. Using hospital mortality as a gold standard, a PS ≥ 36 (predicted mortality ≥ 5%) showed a sensitivity of 73.3%, a specificity of 62.2% and an NPV of 96.4%. PS predicted mortality was ≥5% in 70 (39%) patients and was higher (median 5.2%; IQR: 2.8; 11.8 vs 1.7%; IQR: 1.0; 2.8; p  Conclusion Determination of phase angle