Association between the modified Nutrition Risk in Critically Ill (mNUTRIC) score and clinical outcomes in the intensive care unit: a secondary analysis of a large prospective observational study

Background: Malnutrition in intensive care unit (ICU) patients is associated with adverse clinical outcomes. The modified nutrition risk in the critically ill score (mNUTRIC) was proposed as an appropriate nutritional assessment tool in critically ill patients, but it has not been fully demonstrated and widely used. Our study was conducted to identify the nutritional risk in ICU patients using the mNUTRIC score and explore the relationship between 28-day mortality and high mNUTRIC scores.

Methods: This study is a secondary analysis, the data were extracted from The Beijing Acute Kidney Injury Trial (BAKIT). In total, 9049 patients were admitted consecutively, and 3107 patients with complete clinical data were included in this study. We divided the study population into high nutritional risk (mNUTRIC score ≥ 5 points) and low nutritional risk (mNUTRIC score < 5 points) groups. The predictive capacity of the mNUTRIC score was studied by receiver operating characteristic (ROC) curve analysis, appropriate cut-off was identified by highest combined sensitivity and specificity using Youden's index. The significance level was set at 5%.

Results: Among the 3107 patients, the 28-day mortality rate was 17.4% (540 patients died). Nearly 28.2% of patients admitted to the ICU were at risk of malnutrition, high nutritional risk patients were older (P < 0.001), with higher illness severity scores than low nutritional risk patients. Multivariate analysis revealed that the mNUTRIC score was an independent risk factor for 28-day mortality and mortality increased with increasing scores (p = 0.000). The calculated area under curve (AUC) for the mNUTRIC score was 0.763 (CI 0.740-0.786). According to Youden's index, we found a suitable cut-off > 4 for the mNUTRIC score to predict the 28-day mortality.

Conclusions: Patients admitted to the ICU were at high risk of malnutrition, and a high mNUTRIC score was associated with increased ICU length of stay and higher mortality. More large prospective studies are needed to demonstrate the validity of this score.

Trial registration: This study was registered at www.chictr.org.cn (registration number Chi CTR-ONC-11001875 ). Registered on 14 December 2011.