Length of hospital stay reduced with nutritional supplementation, study finds

By Olivia Haslam

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Length of hospital stay reduced with nutritional supplementation, study finds

Related tags Nutrition albumin Cholesterol supplementation Gastroenterology mortality

A new prospective cohort study proposes high-calorie and high-protein nutritional supplementation within 48h of admission correlates with lower mortality in hospital patients.

The study, conducted in an internal medicine and gastroenterology unit in Italy, also found that length of stay and mortality rates can be reliably predicted using a nutritional status score.

The CONUT score is a nutrition-related tool for predicting mortality at admission and stratifying the risk of a longer length of stay (LOS). The score is calculated by totalling serum albumin, total cholesterol (TC) level and total lymphocyte count (TLC), with a higher score meaning higher patient risk. It has previously been proven​ to correlate with nutrition grading and to have high rates of accuracy in predicting clinical outcomes and morbidity in patients. However, while studies have been performed to demonstrate that higher CONUT score predicts a higher LOS and in-hospital mortality risk​, there has previously been lacking data on CONUT studies' application in Western countries.

The authors of the study aimed to test Controlling Nutritional Status (CONUT) at admission stages as a predictive score of hospital outcomes.

The authors state: “Given the relevance and ease of performing, health professionals should be incentivised to use the CONUT score in clinical practice to prompt personalised nutritional support. Indeed, we observed that early nutritional intervention (within 48h of admission) could reduce in-hospital mortality.”


According to estimates,​ 30% of hospitalised patients in both the United States and Europe have malnutrition or are at risk of it.

A previous hospital report​ in Italy found that over half the patients were at risk of malnutrition, and more than a third were already malnourished when admitted. Malnutrition is linked to an increased risk of infections​, significantly higher sepsis mortality​, an increased risk of pressure ulcers, and a worse outcome of wound healing, in addition to being an independent risk factor for poor postoperative outcomes in surgical patients​.

Pre-existing malnutrition is known to affect critical illness patients' major outcomes​, such as the length of time spent on ventilation, LOS in intensive care units (ICU), or infections.

The authors of the new report also hypothesise that due to the GI tract's role in nutrient absorption, hospital malnutrition may be more noticeable in a gastroenterology department​.

The authors state: “While focusing on diagnosis or treatment, clinicians frequently fail to recognise hospital malnutrition in daily clinical practice, and the assessment of clinical nutrition of hospitalised patients is still undervalued​. This is likely because clinicians are unaware of the issue.”

Internationally there have been a number of screening tools released​, including the Malnutrition Universal Screening Tool (MUST) and Nutrition Risk Screening 2002 (NRS-2002), and the Global Leadership Initiative on Malnutrition (GLIM). The authors of the study suggest that the application of validated tools appears to be insufficient​ in hospital settings despite widespread dissemination among scientific sessions, possibly due to a lack of staff, time, and training.

The authors suggest: “Despite a large diffusion among scientific sessions, the real application of such validated tools appears insufficient in hospital settings​, perhaps due to a lack of training, staff, and time.

“The Controlling Nutritional status (CONUT) score, a simple index calculated using serum routine analysis, and has been proven not only to correlate with malnutrition grade​ but also to have a high predictive value concerning clinical outcomes and morbidity.”


A single-centre, observational, prospective, cohort study was conducted. All patients included in the study were over 18 years old, and were admitted to the Internal Medicine and Gastroenterology ward at the Fondazione Policlinico Agostino Gemelli IRCCS, Rome, Italy, between March 2021 to February 2022.

Patients admitted to the centre as part of the study were divided into four CONUT classes based on points calculated: normal (0–1); mild (2–4); moderate (5–8); and severe(9–12)

The primary outcome of the study analysis was to measure length of stay (LOS) and the secondary one was in-hospital mortality.

203 patients were evaluated, of which 127 were males and 76 were females. Most patients (68.5%) were admitted from the emergency department. Out of patients enrolled, 21.7% patients had a normal status, 32.5% had a mild impairment, 33.5% had a moderate impairment, and 12.3% a severe impairment. The mean LOS was 8.24 ± 5.75 days, and nine patients died.

The results found that a moderate-severe CONUT correlated with a higher LOS. In fact, at admission, patients reporting a CONUT score ≥ 5 points had nearly 90% probability of a longer LOS than those with a lower score. 

And nutritional supplementation within 48h from admission correlated with lower mortality, with CONUT reliably predicting LOS and in-hospital mortality in medical wards.

Nutritional Supplementation

The findings showed how nutritional supplementation, when given within 48 hours of admission, can cut the risk of mortality by almost 90%. Adhering to the recommendations of the clinical nutrition team involved in the study, the nutritional supplementation included both high-calorie and high-protein oral nutritional supplements (ONS) as well as artificial enteral or parenteral nutrition.

Higher BMI was also associated with lower mortality risk, as well as nutritional supplementation received within 48 h from admission.

The results mirrored those of another previous study​, which demonstrated, in a large number of patients at nutritional risk, that an individualised nutritional support in medical inpatients could reduce adverse events and in-hospital mortality.

Additionally this study collected data​ on the occurrence of refeeding syndrome ​(RS), which can happen when malnourished patients receive artificial refeeding. It is defined by shifts in fluids and electrolytes in the body which can affect hormonal and metabolic changes, which can then cause serious clinical complications or death. The authors of the study conclude: “In regard to this study, [RS] is significantly higher in the moderate-severe CONUT class. This confirms the efficacy of CONUT as a nutritional predictive score.”


There were some limitations to the study. The authors stated: “The main limitations are the monocentric design and the small number of deaths which does not allow us to perform a multivariable analysis, even if this demonstrated the efficiency of the department care.

"Thus, we think that the CONUT value in predicting in-hospital mortality should be further confirmed in other similar prospective studies. Moreover, we did not perform a complete nutritional assessment since this study lacks data about body composition."

They concluded: “Further studies are warranted to correlate the CONUT score with body composition parameters such as body cell mass or muscle mass.”


Journal: Nutrients


“COntrolling NUTritional Status (CONUT) as Predictive Score of Hospital Length of Stay (LOS) and Mortality: A Prospective Cohort Study in an Internal Medicine and Gastroenterology Unit in Italy”

Authors: Emanuele Rinninella, Raffaele Borriello, Marco D’Angelo, Tiziano Galasso, Marco Cintoni, Pauline Raoul, Michele Impagnatiello, Brigida Eleonora Annicchiarico, Antonio Gasbarrini and Maria Cristina Mele.

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